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

Conflicts:
- `README.md`:
  Upstream changed their README, we have our own.
  Kept ours.
- `app/helpers/application_helper.rb`:
  Minor code style fix upstream, on a line that is different in glitch-soc
  due to the different theming system.
  Applied the code style fix to our own code.
- `app/views/settings/preferences/appearance/show.html.haml`:
  Code style fix on a line next to lines exclusive to glitch-soc.
  Applied upstream changes.
- `yarn.lock`:
  Upstream updated a dependency textually close to a glitch-soc-only
  dependency.
  Updated the dependency like upstream did.

app/helpers/application_helper.rb

@@ -112,7 +112,7 @@ module ApplicationHelper
   def fa_icon(icon, attributes = {})
     class_names = attributes[:class]&.split(' ') || []
     class_names << 'fa'
-    class_names += icon.split(' ').map { |cl| "fa-#{cl}" }
+    class_names += icon.split.map { |cl| "fa-#{cl}" }
 
     content_tag(:i, nil, attributes.merge(class: class_names.join(' ')))
   end
@@ -164,7 +164,7 @@ module ApplicationHelper
   end
 
   def body_classes
-    output = (@body_classes || '').split(' ')
+    output = (@body_classes || '').split
     output << "flavour-#{current_flavour.parameterize}"
     output << "skin-#{current_skin.parameterize}"
     output << 'system-font' if current_account&.user&.setting_system_font_ui