update readme

Author: ipcjs

README.md

@@ -103,7 +103,7 @@ And you can still add your custom error messages.
 
 ### Setup
 
-To allow for localization of default error messages within your app, add `FormBuilderLocalizations.delegate` in the list of your app's `localizationsDelegates`
+The default error message is in English. To allow for localization of default error messages within your app, add `FormBuilderLocalizations.delegate` in the list of your app's `localizationsDelegates`
 
 ```dart
   return MaterialApp(
@@ -171,6 +171,10 @@ TextFormField(
 ),
 ```
 
+### Modify the default error message in a specific language
+
+see [override_form_builder_localizations_en](example/lib/override_form_builder_localizations_en.dart) for more detail.
+
 ## Support
 
 ### Contribute

example/lib/main.dart

@@ -23,6 +23,7 @@ class MyApp extends StatelessWidget {
       ],
       localizationsDelegates: const [
         ...GlobalMaterialLocalizations.delegates,
+        // Placed in front of `FormBuilderLocalizations.delegate`
         OverrideFormBuilderLocalizationsEn.delegate,
         FormBuilderLocalizations.delegate,
       ],

example/lib/override_form_builder_localizations_en.dart

@@ -12,6 +12,7 @@ class OverrideFormBuilderLocalizationsEn
 
   static const List<Locale> supportedLocales = [Locale('en')];
 
+  // Override a field and return your translation.
   @override
   String get requiredErrorText => 'override: This field cannot be empty.';
 }