add leave words

lib/apps/group/detail.dart

@@ -215,7 +215,7 @@ class _GroupChatDetailState extends State<GroupChatDetail> {
                     context: context,
                     builder: (BuildContext context) {
                       return AlertDialog(
-                        title: Text(lang.delete),
+                        title: Text(lang.leave),
                         content: Text(_group.name,
                           style: TextStyle(color: color.primary)),
                         actions: [
@@ -245,7 +245,7 @@ class _GroupChatDetailState extends State<GroupChatDetail> {
                 return <PopupMenuEntry<int>>[
                   menuItem(Color(0xFF6174FF), 0, Icons.add_rounded, lang.addFriend),
                   menuItem(Color(0xFF6174FF), 1, Icons.create_rounded, lang.rename),
-                  menuItem(Colors.red, 2, Icons.delete_rounded, lang.delete),
+                  menuItem(Colors.red, 2, Icons.delete_rounded, lang.leave),
                 ];
               },
             )

lib/l10n/localizations.dart

@@ -80,6 +80,7 @@ abstract class AppLocalizations {
   String get file;
   String get delete;
   String get deleteImmediate;
+  String get leave;
   String get open;
   String get unknown;
   String get create;

lib/l10n/localizations_en.dart

@@ -85,6 +85,8 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get deleteImmediate => 'Delete Immediately';
   @override
+  String get leave => 'Leave';
+  @override
   String get open => 'Open';
   @override
   String get unknown => 'Unknown';

lib/l10n/localizations_zh.dart

@@ -85,6 +85,8 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get deleteImmediate => '立即删除';
   @override
+  String get leave => '退出';
+  @override
   String get open => '打开';
   @override
   String get unknown => '未知';