fix(tags): use forum description for meta description on tags homepage (#4557)

Author: imorland

extensions/tags/src/Content/Tags.php

@@ -92,7 +92,8 @@ public function __invoke(Document $document, Request $request)
 
         $defaultRoute = $this->settings->get('default_route');
         $document->title = $this->translator->trans('flarum-tags.forum.all_tags.meta_title_text');
-        $document->meta['description'] = $this->translator->trans('flarum-tags.forum.all_tags.meta_description_text');
+        $document->meta['description'] = $this->settings->get('forum_description')
+            ?: $this->translator->trans('flarum-tags.forum.all_tags.meta_description_text');
         $document->content = $this->view->make('tags::frontend.content.tags', compact('primaryTags', 'secondaryTags', 'children'));
         $document->canonicalUrl = $this->url->to('forum')->base().($defaultRoute === '/tags' ? '' : $request->getUri()->getPath());
         $document->payload['apiDocument'] = $apiDocument;