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

Conflicts:
	README.md
	app/controllers/statuses_controller.rb
	app/lib/feed_manager.rb
	config/navigation.rb
	spec/lib/feed_manager_spec.rb

Conflicts were resolved by taking both versions for each change.
This means the two filter systems (glitch-soc's keyword mutes and tootsuite's
custom filters) are in place, which will be changed in a follow-up commit.

config/settings.yml

@@ -27,6 +27,7 @@ defaults: &defaults
   delete_modal: true
   auto_play_gif: false
   display_sensitive_media: false
+  preview_sensitive_media: false
   reduce_motion: false
   system_font_ui: false
   noindex: false