Update documentation.

Author: davidmorgan

README.md

@@ -5,12 +5,17 @@
 Built JSON provides serialization for the
 [Libraries for Object Oriented Dart](https://github.com/google/built_value.dart/blob/master/libraries_for_object_oriented_dart.md#libraries-for-object-oriented-dart).
 
-This allows a complete serializable object oriented data model to built from
+This allows a complete serializable object oriented data model to be based on
 [Enum Classes](https://github.com/google/enum_class.dart#enum-classes-for-dart),
 [Built Collections](https://github.com/google/built_collection.dart#built-collections-for-dart)
 and
 [Built Values](https://github.com/google/built_value.dart#built-values-for-dart).
 
+Built JSON for Java, a separate project, will provide compatible serialization
+for Java, mapping Enum Classes to standard Java enums, Built Collections to
+[Immutable Collections](https://github.com/google/guava/wiki/ImmutableCollectionsExplained)
+and Built Values to [AutoValues](https://github.com/google/auto/tree/master/value#autovalue).
+
 
 ## Examples