Make appearance settings searchable (fixes #5814)

app/src/main/java/eu/kanade/tachiyomi/ui/setting/search/SettingsSearchHelper.kt

@@ -8,6 +8,7 @@ import androidx.preference.PreferenceCategory
 import androidx.preference.PreferenceGroup
 import androidx.preference.PreferenceManager
 import eu.kanade.tachiyomi.ui.setting.SettingsAdvancedController
+import eu.kanade.tachiyomi.ui.setting.SettingsAppearanceController
 import eu.kanade.tachiyomi.ui.setting.SettingsBackupController
 import eu.kanade.tachiyomi.ui.setting.SettingsBrowseController
 import eu.kanade.tachiyomi.ui.setting.SettingsController
@@ -30,6 +31,7 @@ object SettingsSearchHelper {
      */
     private val settingControllersList: List<KClass<out SettingsController>> = listOf(
         SettingsAdvancedController::class,
+        SettingsAppearanceController::class,
         SettingsBackupController::class,
         SettingsBrowseController::class,
         SettingsDownloadController::class,