Nicer linebreaks

pkgs/messages/example/lib/AboutPage_en_empty.g.dart

@@ -1 +1,2 @@
-/// This is a helper file for deferred loading of the messages for locale en, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale en,
+// generated by `dart run messages`.

pkgs/messages/example/lib/AboutPage_fr_empty.g.dart

@@ -1 +1,2 @@
-/// This is a helper file for deferred loading of the messages for locale fr, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale fr,
+// generated by `dart run messages`.

pkgs/messages/example/lib/AboutPage_messages.g.dart

@@ -1,6 +1,7 @@
 // Generated by package:messages_builder.
 
-// ignore_for_file: non_constant_identifier_names
+// ignore_for_file: library_prefixes, non_constant_identifier_names
+// ignore_for_file: unused_import
 
 import 'package:intl/intl.dart';
 import 'package:messages/messages_json.dart';

pkgs/messages/example/lib/HomePage_de_empty.g.dart

@@ -1 +1,2 @@
-/// This is a helper file for deferred loading of the messages for locale de, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale de,
+// generated by `dart run messages`.

pkgs/messages/example/lib/HomePage_en_empty.g.dart

@@ -1 +1,2 @@
-/// This is a helper file for deferred loading of the messages for locale en, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale en,
+// generated by `dart run messages`.

pkgs/messages/example/lib/HomePage_messages.g.dart

@@ -1,6 +1,7 @@
 // Generated by package:messages_builder.
 
-// ignore_for_file: non_constant_identifier_names
+// ignore_for_file: library_prefixes, non_constant_identifier_names
+// ignore_for_file: unused_import
 
 import 'package:intl/intl.dart';
 import 'package:messages/messages_json.dart';

pkgs/messages/examples_flutter/my_application/lib/src/my_app_de_DE_empty.g.dart

@@ -1 +1,2 @@
-/// This is a helper file for deferred loading of the messages for locale de_DE, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale de_DE,
+// generated by `dart run messages`.

pkgs/messages/examples_flutter/my_application/lib/src/my_app_en_US_empty.g.dart

@@ -1 +1,2 @@
-/// This is a helper file for deferred loading of the messages for locale en_US, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale en_US,
+// generated by `dart run messages`.

pkgs/messages_builder/lib/builder.dart

@@ -72,7 +72,8 @@ class MessageCallingCodeGenerator {
         final file = File(path.join(parentPath.path, '$emptyFilePath.g.dart'));
         await file.create();
         await file.writeAsString('''
-/// This is a helper file for deferred loading of the messages for locale $locale, generated by `dart run messages`.
+// This is a helper file for deferred loading of the messages for locale $locale,
+// generated by `dart run messages`.
 ''');
       }
     }