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

Conflicts:
- `README.md`:
  Minor upstream change, our README is completely different.
  Kept ours.
- `lib/tasks/assets.rake`:
  glitch-soc has extra code to deal with its theming system,
  upstream changed a line that exists in glitch-soc.
  Applied upstream changes.

app/lib/activitypub/activity/create.rb

@@ -285,7 +285,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
     media_attachments
   rescue Addressable::URI::InvalidURIError => e
-    Rails.logger.debug "Invalid URL in attachment: #{e}"
+    Rails.logger.debug { "Invalid URL in attachment: #{e}" }
     media_attachments
   end