Merge commit '68984de5b503791b814d81a85520af256bf43e11' into glitch-soc/merge-upstream

Conflicts:
- `app/views/admin/settings/discovery/show.html.haml`:
  Glitch-soc has an extra setting textually adjacent to a line upstream has changed.
  Applied upstream's change while keeping glitch-soc's setting.

app/javascript/mastodon/components/admin/Dimension.jsx

@@ -85,7 +85,7 @@ export default class Dimension extends PureComponent {
 
     return (
       <div className='dimension'>
-        <h4>{label}</h4>
+        <h2>{label}</h2>
 
         {content}
       </div>

app/javascript/mastodon/components/admin/ImpactReport.jsx

@@ -49,7 +49,7 @@ export default class ImpactReport extends PureComponent {
 
     return (
       <div className='dimension'>
-        <h4><FormattedMessage id='admin.impact_report.title' defaultMessage='Impact summary' /></h4>
+        <FormattedMessage id='admin.impact_report.title' defaultMessage='Impact summary' tagName="h2" />
 
         <table>
           <tbody>

app/javascript/mastodon/components/admin/Retention.jsx

@@ -145,7 +145,7 @@ export default class Retention extends PureComponent {
 
     return (
       <div className='retention'>
-        <h4>{title}</h4>
+        <h2>{title}</h2>
 
         {content}
       </div>

app/javascript/mastodon/components/admin/Trends.jsx

@@ -66,7 +66,7 @@ export default class Trends extends PureComponent {
 
     return (
       <div className='trends trends--compact'>
-        <h4><FormattedMessage id='trends.trending_now' defaultMessage='Trending now' /></h4>
+        <FormattedMessage id='trends.trending_now' defaultMessage='Trending now' tagName='h2' />
 
         {content}
       </div>