Hallo,
Wenn ich das richtig verstehe, möchten Sie hier auf der Suchseite ein Suchsymbol hinzufügen 
Dafür müssen Sie vermutlich die Discourse-Vorlage überschreiben.
So geht’s: Überschreiben von Discourse-Vorlagen. Ich empfehle jedoch, die gesamte Dokumentation zu lesen.
In diesem Fall sieht es ungefähr so aus. Zuerst müssen Sie die Vorlage der Suchseite finden. Hier sind die Vorlagen: https://github.com/discourse/discourse/tree/main/app/assets/javascripts/discourse/app/templates
Die gesuchte Vorlage ist full-page-search.hbs. Man erkennt deutlich, welcher Teil bearbeitet werden muss, um diese Änderung vorzunehmen.
Dies ist der Kopfbereich der Vorlage, den wir bearbeiten werden – das machen wir jedoch etwas später…
<h1 class="search-page-heading">
{{#if this.hasResults}}
<div class="result-count" id="search-result-count" aria-live="polite">
{{html-safe this.resultCountLabel}}
</div>
{{else}}
{{i18n "search.full_page_title"}}
{{/if}}
</h1>
Jetzt wissen wir aufgrund der oben genannten Dokumentation, dass wir so beginnen sollten:
Die Vorlage geht in den Header-Bereich.
<script type="text/x-handlebars" data-template-name="full-page-search">
</script>
Anschließend müssen wir die gesamte Vorlage hineinkopieren:
Sieht so aus
<script type="text/x-handlebars" data-template-name="full-page-search">
<DSection @pageClass="search" @class="search-container">
<ScrollTracker @name="full-page-search" @tag={{this.searchTerm}} @class="hidden" />
<div class="search-header" role="search">
<h1 class="search-page-heading">
{{#if this.hasResults}}
<div class="result-count" id="search-result-count" aria-live="polite">
{{html-safe this.resultCountLabel}}
</div>
{{else}}
{{i18n "search.full_page_title"}}
{{/if}}
</h1>
<div class="search-bar">
<SearchTextField @value={{this.searchTerm}} @class="full-page-search search no-blur search-query" @aria-label={{i18n "search.search_term_label"}} @enter={{action "search" (hash collapseFilters=true)}} @hasAutofocus={{this.hasAutofocus}} @aria-controls="search-result-count" />
<ComboBox @id="search-type" @value={{this.search_type}} @content={{this.searchTypes}} @onChange={{action (mut this.search_type)}} @options={{hash
castInteger=true
}} />
<DButton @action={{action "search" (hash collapseFilters=true)}} @icon="search" @label="search.search_button" @class="btn-primary search-cta" @ariaLabel="search.search_button" @disabled={{this.searchButtonDisabled}} />
</div>
{{#if this.usingDefaultSearchType}}
{{!-- context is only provided when searching from mobile view --}}
{{#if this.context}}
<div class="search-context">
<label>
<Input @type="checkbox" name="searchContext" @checked={{this.searchContextEnabled}} /> {{this.searchContextDescription}}
</label>
</div>
{{/if}}
<div class="search-filters">
<SearchAdvancedOptions @searchTerm={{readonly this.searchTerm}} @onChangeSearchTerm={{action (mut this.searchTerm)}} @search={{action "search" (hash collapseFilters=true)}} @searchButtonDisabled={{this.searchButtonDisabled}} @expandFilters={{this.expandFilters}} />
</div>
{{/if}}
<div class="search-notice">
{{#if this.invalidSearch}}
<div class="fps-invalid">
{{i18n "search.too_short"}}
</div>
{{/if}}
</div>
</div>
<div class="search-advanced">
{{#if this.hasResults}}
{{#if this.usingDefaultSearchType}}
<div class={{this.searchInfoClassNames}} role="region" ariaLabel={{i18n "search.sort_or_bulk_actions"}}>
{{#if this.canBulkSelect}}
<DButton @icon="list" @class="btn-default bulk-select" @title="topics.bulk.toggle" @action={{action "toggleBulkSelect"}} />
{{#if this.selected}}
<DButton @class="btn-default bulk-select-btn" @selected={{this.selected}} @action={{action "showBulkActions"}} @icon="wrench" />
{{/if}}
{{/if}}
{{#if this.bulkSelectEnabled}}
{{#if this.hasUnselectedResults}}
<DButton @icon="check-square" @class="btn-default" @action={{action "selectAll"}} @label="search.select_all" />
{{/if}}
{{#if this.hasSelection}}
<DButton @icon="far-square" @class="btn-default" @action={{action "clearAll"}} @label="search.clear_all" />
{{/if}}
{{/if}}
<div class="sort-by inline-form">
<label>
{{i18n "search.sort_by"}}
</label>
<ComboBox @value={{this.sortOrder}} @content={{this.sortOrders}} @onChange={{action (mut this.sortOrder)}} @id="search-sort-by" @options={{hash
castInteger=true
}} />
</div>
</div>
{{/if}}
{{/if}}
<PluginOutlet @name="full-page-search-below-search-info" @tagName="span" @connectorTagName="div" @args={{hash search=this.searchTerm}} />
{{#if this.searching}}
{{loading-spinner size="medium"}}
{{else}}
<div class="search-results" role="region">
<LoadMore @selector=".fps-result" @action={{action "loadMore"}}>
{{#if this.usingDefaultSearchType}}
<SearchResultEntries @posts={{this.model.posts}} @bulkSelectEnabled={{this.bulkSelectEnabled}} @selected={{this.selected}} @highlightQuery={{this.highlightQuery}} @searchLogId={{this.model.grouped_search_result.search_log_id}} />
<ConditionalLoadingSpinner @condition={{this.loading}}>
{{#unless this.hasResults}}
{{#if this.searchActive}}
<h3>{{i18n "search.no_results"}}</h3>
{{#if this.model.grouped_search_result.error}}
<div class="warning">
{{this.model.grouped_search_result.error}}
</div>
{{/if}}
{{#if this.showSuggestion}}
<div class="no-results-suggestion">
{{i18n "search.cant_find"}}
{{#if this.canCreateTopic}}
<a href {{action "createTopic" this.searchTerm}}>{{i18n "search.start_new_topic"}}</a>
{{#unless this.siteSettings.login_required}}
{{i18n "search.or_search_google"}}
{{/unless}}
{{else}}
{{i18n "search.search_google"}}
{{/if}}
</div>
<GoogleSearch @searchTerm={{this.searchTerm}} />
{{/if}}
{{/if}}
{{/unless}}
{{#if this.hasResults}}
<h3 class="search-footer">
{{#if this.model.grouped_search_result.more_full_page_results}}
{{#if this.isLastPage}}
{{i18n "search.more_results"}}
{{/if}}
{{else}}
{{i18n "search.no_more_results"}}
{{/if}}
</h3>
{{/if}}
</ConditionalLoadingSpinner>
{{else}}
<ConditionalLoadingSpinner @condition={{this.loading}}>
{{#if this.hasResults}}
{{#if this.model.categories.length}}
<h4 class="category-heading">
{{i18n "search.categories"}}
</h4>
<div class="category-items">
{{#each this.model.categories as |category|}}
{{category-link category extraClasses="fps-category-item"}}
{{/each}}
</div>
{{/if}}
{{#if this.model.tags.length}}
<h4 class="tag-heading">
{{i18n "search.tags"}}
</h4>
<div class="tag-items">
{{#each this.model.tags as |tag|}}
<div class="fps-tag-item">
<a href={{tag.url}}>
{{tag.id}}
</a>
</div>
{{/each}}
</div>
{{/if}}
{{#if this.model.users}}
<div class="user-items">
{{#each this.model.users as |user|}}
<UserLink @user={{user}} @class="fps-user-item">
{{avatar user imageSize="large"}}
<div class="user-titles">
{{#if user.name}}
<span class="name">
{{user.name}}
</span>
{{/if}}
<span class="username">
{{user.username}}
</span>
</div>
</UserLink>
{{/each}}
</div>
{{/if}}
{{else}}
{{#if this.searchActive}}
<h3>{{i18n "search.no_results"}}</h3>
{{/if}}
{{/if}}
</ConditionalLoadingSpinner>
{{/if}}
</LoadMore>
</div>
{{/if}}
</div>
</DSection>
</script>
Jetzt können wir den Kopfbereich bearbeiten, den ich zuvor erwähnt habe. In diesem Fall ist dies eine sehr einfache Änderung, aber Sie können auch komplexere Änderungen vornehmen. Stellen Sie sicher, dass Ihre benutzerdefinierte Vorlage immer auf dem neuesten Stand ist. Wenn es Änderungen in der Kernvorlage gibt, sollten Sie auch Ihre benutzerdefinierte Vorlage aktualisieren, damit alles einwandfrei funktioniert. 
In diesem Fall fügen wir einfach ein Symbol {{d-icon "search"}} vor dem Titel der Vollbildseite und vor der Ergebnisanzahl hinzu.
Die vollständige Vorlage sieht so aus
<script type="text/x-handlebars" data-template-name="full-page-search">
<DSection @pageClass="search" @class="search-container">
<ScrollTracker @name="full-page-search" @tag={{this.searchTerm}} @class="hidden" />
<div class="search-header" role="search">
<h1 class="search-page-heading">
{{#if this.hasResults}}
<div class="result-count" id="search-result-count" aria-live="polite">
{{d-icon "search"}}
{{html-safe this.resultCountLabel}}
</div>
{{else}}
{{d-icon "search"}}
{{i18n "search.full_page_title"}}
{{/if}}
</h1>
<div class="search-bar">
<SearchTextField @value={{this.searchTerm}} @class="full-page-search search no-blur search-query" @aria-label={{i18n "search.search_term_label"}} @enter={{action "search" (hash collapseFilters=true)}} @hasAutofocus={{this.hasAutofocus}} @aria-controls="search-result-count" />
<ComboBox @id="search-type" @value={{this.search_type}} @content={{this.searchTypes}} @onChange={{action (mut this.search_type)}} @options={{hash
castInteger=true
}} />
<DButton @action={{action "search" (hash collapseFilters=true)}} @icon="search" @label="search.search_button" @class="btn-primary search-cta" @ariaLabel="search.search_button" @disabled={{this.searchButtonDisabled}} />
</div>
{{#if this.usingDefaultSearchType}}
{{!-- context is only provided when searching from mobile view --}}
{{#if this.context}}
<div class="search-context">
<label>
<Input @type="checkbox" name="searchContext" @checked={{this.searchContextEnabled}} /> {{this.searchContextDescription}}
</label>
</div>
{{/if}}
<div class="search-filters">
<SearchAdvancedOptions @searchTerm={{readonly this.searchTerm}} @onChangeSearchTerm={{action (mut this.searchTerm)}} @search={{action "search" (hash collapseFilters=true)}} @searchButtonDisabled={{this.searchButtonDisabled}} @expandFilters={{this.expandFilters}} />
</div>
{{/if}}
<div class="search-notice">
{{#if this.invalidSearch}}
<div class="fps-invalid">
{{i18n "search.too_short"}}
</div>
{{/if}}
</div>
</div>
<div class="search-advanced">
{{#if this.hasResults}}
{{#if this.usingDefaultSearchType}}
<div class={{this.searchInfoClassNames}} role="region" ariaLabel={{i18n "search.sort_or_bulk_actions"}}>
{{#if this.canBulkSelect}}
<DButton @icon="list" @class="btn-default bulk-select" @title="topics.bulk.toggle" @action={{action "toggleBulkSelect"}} />
{{#if this.selected}}
<DButton @class="btn-default bulk-select-btn" @selected={{this.selected}} @action={{action "showBulkActions"}} @icon="wrench" />
{{/if}}
{{/if}}
{{#if this.bulkSelectEnabled}}
{{#if this.hasUnselectedResults}}
<DButton @icon="check-square" @class="btn-default" @action={{action "selectAll"}} @label="search.select_all" />
{{/if}}
{{#if this.hasSelection}}
<DButton @icon="far-square" @class="btn-default" @action={{action "clearAll"}} @label="search.clear_all" />
{{/if}}
{{/if}}
<div class="sort-by inline-form">
<label>
{{i18n "search.sort_by"}}
</label>
<ComboBox @value={{this.sortOrder}} @content={{this.sortOrders}} @onChange={{action (mut this.sortOrder)}} @id="search-sort-by" @options={{hash
castInteger=true
}} />
</div>
</div>
{{/if}}
{{/if}}
<PluginOutlet @name="full-page-search-below-search-info" @tagName="span" @connectorTagName="div" @args={{hash search=this.searchTerm}} />
{{#if this.searching}}
{{loading-spinner size="medium"}}
{{else}}
<div class="search-results" role="region">
<LoadMore @selector=".fps-result" @action={{action "loadMore"}}>
{{#if this.usingDefaultSearchType}}
<SearchResultEntries @posts={{this.model.posts}} @bulkSelectEnabled={{this.bulkSelectEnabled}} @selected={{this.selected}} @highlightQuery={{this.highlightQuery}} @searchLogId={{this.model.grouped_search_result.search_log_id}} />
<ConditionalLoadingSpinner @condition={{this.loading}}>
{{#unless this.hasResults}}
{{#if this.searchActive}}
<h3>{{i18n "search.no_results"}}</h3>
{{#if this.model.grouped_search_result.error}}
<div class="warning">
{{this.model.grouped_search_result.error}}
</div>
{{/if}}
{{#if this.showSuggestion}}
<div class="no-results-suggestion">
{{i18n "search.cant_find"}}
{{#if this.canCreateTopic}}
<a href {{action "createTopic" this.searchTerm}}>{{i18n "search.start_new_topic"}}</a>
{{#unless this.siteSettings.login_required}}
{{i18n "search.or_search_google"}}
{{/unless}}
{{else}}
{{i18n "search.search_google"}}
{{/if}}
</div>
<GoogleSearch @searchTerm={{this.searchTerm}} />
{{/if}}
{{/if}}
{{/unless}}
{{#if this.hasResults}}
<h3 class="search-footer">
{{#if this.model.grouped_search_result.more_full_page_results}}
{{#if this.isLastPage}}
{{i18n "search.more_results"}}
{{/if}}
{{else}}
{{i18n "search.no_more_results"}}
{{/if}}
</h3>
{{/if}}
</ConditionalLoadingSpinner>
{{else}}
<ConditionalLoadingSpinner @condition={{this.loading}}>
{{#if this.hasResults}}
{{#if this.model.categories.length}}
<h4 class="category-heading">
{{i18n "search.categories"}}
</h4>
<div class="category-items">
{{#each this.model.categories as |category|}}
{{category-link category extraClasses="fps-category-item"}}
{{/each}}
</div>
{{/if}}
{{#if this.model.tags.length}}
<h4 class="tag-heading">
{{i18n "search.tags"}}
</h4>
<div class="tag-items">
{{#each this.model.tags as |tag|}}
<div class="fps-tag-item">
<a href={{tag.url}}>
{{tag.id}}
</a>
</div>
{{/each}}
</div>
{{/if}}
{{#if this.model.users}}
<div class="user-items">
{{#each this.model.users as |user|}}
<UserLink @user={{user}} @class="fps-user-item">
{{avatar user imageSize="large"}}
<div class="user-titles">
{{#if user.name}}
<span class="name">
{{user.name}}
</span>
{{/if}}
<span class="username">
{{user.username}}
</span>
</div>
</UserLink>
{{/each}}
</div>
{{/if}}
{{else}}
{{#if this.searchActive}}
<h3>{{i18n "search.no_results"}}</h3>
{{/if}}
{{/if}}
</ConditionalLoadingSpinner>
{{/if}}
</LoadMore>
</div>
{{/if}}
</div>
</DSection>
</script>
Hoffe, das hilft
