Do not know where to add, I want to share. In this example, you can see how to change the individual elements in the design. I do not know how true this approach is.
Add:
PLAGIN/assets/javascripts/discourse/helpers/catid-img.js.es6
import { registerUnbound } from 'discourse-common/lib/helpers';
var get = Em.get,
escapeExpression = Handlebars.Utils.escapeExpression;
export function categoryBadgeHTML(category, opts) {
opts = opts || {};
let categoryID = escapeExpression(get(category, 'id'));
let img = Discourse.Category.findById(categoryID).uploaded_logo.url;
let categoryName = escapeExpression(get(category, 'name'));
let url = opts.url ? opts.url : Discourse.getURL("/c/") + Discourse.Category.slugFor(category);
return `<a class="catid-url" title="${categoryName}" href="${url}"><img src="${img}" alt="${categoryName}" class="catid-logo"></a>`;
}
export function categoryLinkHTML(category, options) {
var categoryOptions = {};
return new Handlebars.SafeString(categoryBadgeHTML(category, categoryOptions));
}
registerUnbound('catid-img', categoryLinkHTML);
Add:

{{catid-img topic.category}}
The output of category icons:
P.S. perhaps this can be done in another way, more easier, but it is easier for me to add 1 file to the plugin.
