Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Our README.md files are completely different. Discarded upstream changes.
- `app/javascript/core/admin.js`:
  Updating rails-ujs, no real conflict, but a comment to close to changed
  code. Various glitch-soc-only files have been updated to match those changes,
  though.
- `package.json`:
  No real conflict, just an additional dependency in glitch-soc that was too
  close to something updated upstream. Took upstream's changes.

app/javascript/mastodon/features/compose/components/action_bar.js

@@ -16,6 +16,7 @@ const messages = defineMessages({
   mutes: { id: 'navigation_bar.mutes', defaultMessage: 'Muted users' },
   filters: { id: 'navigation_bar.filters', defaultMessage: 'Muted words' },
   logout: { id: 'navigation_bar.logout', defaultMessage: 'Logout' },
+  bookmarks: { id: 'navigation_bar.bookmarks', defaultMessage: 'Bookmarks' },
 });
 
 export default @injectIntl
@@ -42,6 +43,7 @@ class ActionBar extends React.PureComponent {
     menu.push(null);
     menu.push({ text: intl.formatMessage(messages.follow_requests), to: '/follow_requests' });
     menu.push({ text: intl.formatMessage(messages.favourites), to: '/favourites' });
+    menu.push({ text: intl.formatMessage(messages.bookmarks), to: '/bookmarks' });
     menu.push({ text: intl.formatMessage(messages.lists), to: '/lists' });
     menu.push(null);
     menu.push({ text: intl.formatMessage(messages.mutes), to: '/mutes' });