Add new Chinese translation

lib/l10n/app_localizations.dart

@@ -13,7 +13,7 @@ import 'app_localizations_fr.dart';
 import 'app_localizations_hr.dart';
 import 'app_localizations_it.dart';
 import 'app_localizations_sl.dart';
-
+import 'app_localizations_zh.dart';
 // ignore_for_file: type=lint
 
 /// Callers can lookup localized strings with an instance of AppLocalizations
@@ -108,6 +108,7 @@ abstract class AppLocalizations {
     Locale('hr'),
     Locale('it'),
     Locale('sl'),
+    Locale('zh'),
   ];
 
   /// The application title
@@ -4225,6 +4226,7 @@ class _AppLocalizationsDelegate
     'hr',
     'it',
     'sl',
+    'zh',
   ].contains(locale.languageCode);
 
   @override
@@ -4250,6 +4252,8 @@ AppLocalizations lookupAppLocalizations(Locale locale) {
       return AppLocalizationsIt();
     case 'sl':
       return AppLocalizationsSl();
+    case 'zh':
+      return AppLocalizationsZh();
   }
 
   throw FlutterError(