implemented automatic (default) language feature in app

Author: amitamrutiya

lib/Constants/languages.dart

@@ -0,0 +1,24 @@
+const Languages = {
+  'auto': 'Automatic',
+  'en': 'English',
+  'hi': 'हिन्दी',
+  'cs': 'Čeština',
+  'de': 'Deutsch',
+  'es': 'Español',
+  'fr': 'Français',
+  'it': 'italiano',
+  'hu': 'Magyar',
+  'nl': 'Nederlands',
+  'no': 'norsk',
+  'pl': 'Polskie',
+  'pt': 'português',
+  'ru': 'русский язык',
+  'ro': 'Romanian',
+  'fi': 'suomi',
+  'sv': 'svenska',
+  'uk': 'українська мова',
+  'ko': '한국어',
+  'ja': '日本語',
+  'zh': '中文(繁體)',
+  'ar': 'اَلْعَرَبِيَّةُ',
+};

lib/l10n/l10n.dart

@@ -0,0 +1,7 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+export 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+extension AppLocalizationsX on BuildContext {
+  AppLocalizations get l10n => AppLocalizations.of(this);
+}