Add note to generated file how to re-generate it.

Author: greenrobot-team

generator/lib/src/code_chunks.dart

@@ -10,6 +10,10 @@ class CodeChunks {
           ModelInfo model, List<String> imports, Pubspec? pubspec) =>
       """
     // GENERATED CODE - DO NOT MODIFY BY HAND
+    // This code was generated by ObjectBox. To update it run the generator again:
+    // With a Flutter package, run `flutter pub run build_runner build`.
+    // With a Dart package, run `dart run build_runner build`.
+    // See also https://docs.objectbox.io/getting-started#generate-objectbox-code
 
     // ignore_for_file: camel_case_types
 

objectbox/CHANGELOG.md

@@ -1,5 +1,7 @@
 ## latest
 
+* Add note to `objectbox.g.dart` on how to re-generate (update) it.
+
 ## 1.4.0 (2022-02-22)
 
 * Support [ObjectBox Admin](https://docs.objectbox.io/data-browser) for Android apps to browse