Discourse类别标题主题组件

[nathank (Nathan Kershaw)]

我已为此 PR 添加了对备用锁图标的支持（来自 https://meta.discourse.org/t/category-icons/104683）：

Add feature: alternative lock icon

@StefanoCecere

this component is much better than category-banners and should be the new default!

完全同意！