Better describe current status

README.md

@@ -34,6 +34,28 @@ Please see below for the documentation relevant to you.
   - [![API Docs](http://img.shields.io/badge/yard-docs-blue.svg)](http://www.rubydoc.info/github/rails-api/active_model_serializers/0-8-stable)
 
 
+## Status of AMS
+
+*Status*:
+
+- ❗️ All existing PRs against master will need to be closed and re-opened against 0-10-stable, if so desired
+- ❗️ Master, for the moment, won't have any released version of AMS on it.
+
+*Changes to 0.10.x maintenance*:
+
+- The 0.10.x version has become a huge maintenance version.  We had hoped to get it in shape for a 1.0 release, but it is clear that isn't going to happen.  Almost none of the maintainers from 0.8, 0.9, or earlier 0.10 are still working on AMS. We'll continue to maintain 0.10.x on the 0-10-stable branch, but maintainers won't otherwise be actively developing on it
+  - We may choose to make a 0.11.x ( 0-11-stable) release based on 0-10-stable that just removes the deprecations.
+
+*What's happening to AMS*:
+
+- There's been a lot of churn around AMS since it began back in [Rails 3.2](CHANGELOG-prehistory.md) and a lot of new libraries are around and the JSON:API spec has reached 1.0.
+- If there is to be a 1.0 release of AMS, it will need to address the general needs of serialization in much the way ActiveJob can be used with different workers.
+- The next major release *is* in development. We're starting simple and avoiding, at least at the outset, all the complications in AMS version, especially all the implicit behavior from guessing the serializer, to the association's serializer, to the serialization type, etc.
+- The basic idea is that models to serializers are a one to many relationship.  Everything will need to be explicit.  If you want to serialize a User with a UserSerializer, you'll need to call it directly.  The serializer will essentially be for defining a basic JSON:API resource object: id, type, attributes, and relationships. The serializer will have an as_json method and can be told which fields (attributes/relationships) to serialize to JSON and will likely *not* know serialize any more than the relations id and type.  Serializing anything more about the relations would require code that called a serializer. (This is still somewhat in discussion).
+- If this works out, the idea is to get something into Rails that existing libraries can use.
+
+See [PR 2121](https://github.com/rails-api/active_model_serializers/pull/2121) where these changes were introduced for more information and any discussion.
+
 ## High-level behavior
 
 ## Architecture