Change settings area to be separated into categories in admin UI (#19407)

And update all descriptions

app/controllers/admin/settings/about_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Admin::Settings::AboutController < Admin::SettingsController
+  private
+
+  def after_update_redirect_path
+    admin_settings_about_path
+  end
+end

app/controllers/admin/settings/appearance_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Admin::Settings::AppearanceController < Admin::SettingsController
+  private
+
+  def after_update_redirect_path
+    admin_settings_appearance_path
+  end
+end

app/controllers/admin/settings/branding_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Admin::Settings::BrandingController < Admin::SettingsController
+  private
+
+  def after_update_redirect_path
+    admin_settings_branding_path
+  end
+end

app/controllers/admin/settings/content_retention_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Admin::Settings::ContentRetentionController < Admin::SettingsController
+  private
+
+  def after_update_redirect_path
+    admin_settings_content_retention_path
+  end
+end

app/controllers/admin/settings/discovery_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Admin::Settings::DiscoveryController < Admin::SettingsController
+  private
+
+  def after_update_redirect_path
+    admin_settings_discovery_path
+  end
+end

app/controllers/admin/settings/registrations_controller.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class Admin::Settings::RegistrationsController < Admin::SettingsController
+  private
+
+  def after_update_redirect_path
+    admin_settings_registrations_path
+  end
+end