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

Conflicts:
- README.md
- app/helpers/statuses_helper.rb
  Upstream moved account helpers to their own file, we had extra
  helpers there, moved too.
- app/lib/sanitize_config.rb
- app/models/user.rb
- app/serializers/initial_state_serializer.rb
- config/locales/simple_form.en.yml
- spec/lib/sanitize_config_spec.rb

app/models/media_attachment.rb

@@ -87,6 +87,7 @@ class MediaAttachment < ApplicationRecord
       convert_options: {
         output: {
           'loglevel' => 'fatal',
+          'map_metadata' => '-1',
           'q:a' => 2,
         },
       },