docs: add description for appearance settings

- Added description for settings tab

Author: fulleni

lib/l10n/app_localizations.dart

@@ -974,7 +974,7 @@ abstract class AppLocalizations {
   /// **'Configure your personal preferences for the Dashboard interface, encompassing visual presentation and language selection.'**
   String get settingsPageDescription;
 
-  /// No description provided for @appearanceSettingsDescription.
+  /// Description for the Appearance settings tab
   ///
   /// In en, this message translates to:
   /// **'Adjust the visual characteristics of the Dashboard, including theme, accent colors, and typographic styles.'**

lib/l10n/arb/app_ar.arb

@@ -609,6 +609,9 @@
     "description": "وصف صفحة الإعدادات الرئيسية"
   },
   "appearanceSettingsDescription": "اضبط الخصائص المرئية للوحة القيادة، بما في ذلك السمة وألوان التمييز والأنماط الطباعية.",
+  "@appearanceSettingsDescription": {
+    "description": "وصف تبويب إعدادات المظهر"
+  },
   "loadingHeadlines": "جاري تحميل العناوين الرئيسية",
   "@loadingHeadlines": {
     "description": "عنوان حالة تحميل العناوين الرئيسية"

lib/l10n/arb/app_en.arb

@@ -609,6 +609,9 @@
     "description": "Description for the main settings page"
   },
   "appearanceSettingsDescription": "Adjust the visual characteristics of the Dashboard, including theme, accent colors, and typographic styles.",
+  "@appearanceSettingsDescription": {
+    "description": "Description for the Appearance settings tab"
+  },
   "loadingHeadlines": "Loading Headlines",
   "@loadingHeadlines": {
     "description": "Headline for loading state of headlines"