Add permission icon

extensions/likes/js/admin/src/main.js

@@ -5,6 +5,7 @@ import PermissionGrid from 'flarum/components/PermissionGrid';
 app.initializers.add('likes', () => {
   extend(PermissionGrid.prototype, 'replyItems', items => {
     items.add('likePosts', {
+      icon: 'thumbs-o-up',
       label: 'Like posts',
       permission: 'discussion.likePosts'
     });