Link v0.1 release hygiene note

Author: HDauven

README.md

@@ -120,6 +120,7 @@ Additional documentation:
 - [Provider API](docs/provider-api.md)
 - [Architecture](docs/ARCHITECTURE.md)
 - [Security notes](docs/SECURITY.md)
+- [v0.1 release hygiene](docs/RELEASE_HYGIENE_v0.1.md)
 - [Contributing](CONTRIBUTING.md)
 
 ## Development