Better themeing support!!

config/locales/simple_form.en.yml

@@ -13,6 +13,7 @@ en:
           one: <span class="note-counter">1</span> character left
           other: <span class="note-counter">%{count}</span> characters left
         setting_noindex: Affects your public profile and status pages
+        setting_theme: Affects how Mastodon looks when you're logged in from any device.
       imports:
         data: CSV file exported from another Mastodon instance
       sessions:
@@ -44,6 +45,7 @@ en:
         setting_noindex: Opt-out of search engine indexing
         setting_system_font_ui: Use system's default font
         setting_unfollow_modal: Show confirmation dialog before unfollowing someone
+        setting_theme: Site theme
         severity: Severity
         type: Import type
         username: Username