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

Conflicts:
- `app/models/form/admin_settings.rb`:
  New setting added upstream. Ported it.
- `app/views/statuses/_simple_status.html.haml`:
  Upstream removed RTL classes. Did the same.
- `config/settings.yml`:
  New setting added upstream. Ported it.

spec/controllers/admin/instances_controller_spec.rb

@@ -9,10 +9,10 @@ RSpec.describe Admin::InstancesController, type: :controller do
 
   describe 'GET #index' do
     around do |example|
-      default_per_page = Account.default_per_page
-      Account.paginates_per 1
+      default_per_page = Instance.default_per_page
+      Instance.paginates_per 1
       example.run
-      Account.paginates_per default_per_page
+      Instance.paginates_per default_per_page
     end
 
     it 'renders instances' do