Add descriptions to trending features in admin UI (#17677)

app/views/admin/trends/statuses/_status.html.haml

@@ -22,6 +22,9 @@
     - if status.language.present?
       •
       = standard_locale_name(status.language)
+    - if status.trendable? && !status.account.discoverable?
+      •
+      = t('admin.trends.statuses.not_discoverable')
     - if status.trendable? && (rank = Trends.statuses.rank(status.id))
       •
       %abbr{ title: t('admin.trends.tags.current_score', score: Trends.statuses.score(status.id)) }= t('admin.trends.tags.trending_rank', rank: rank + 1)

app/views/admin/trends/statuses/index.html.haml

@@ -4,6 +4,10 @@
 - content_for :header_tags do
   = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
 
+%p= t('admin.trends.statuses.description_html')
+
+%hr.spacer/
+
 = form_tag admin_trends_statuses_path, method: 'GET', class: 'simple_form' do
   - Trends::StatusFilter::KEYS.each do |key|
     = hidden_field_tag key, params[key] if params[key].present?