Merge pull request #20 from jedevc/readme-more-details

docs: add experimental info and support details to README

Author: jedevc

README.md

@@ -1,20 +1,32 @@
-[![CI Status](https://img.shields.io/github/actions/workflow/status/docker/go-imageinspect/ci.yml?label=ci&logo=github&style=flat-square)](https://github.com/docker/go-imageinspect/actions?query=workflow%3Aci)
+# go-imageinspect
 
-## About
+[![CI Status](https://img.shields.io/github/actions/workflow/status/docker/go-imageinspect/ci.yml?label=ci&logo=github&style=flat-square)](https://github.com/docker/go-imageinspect/actions?query=workflow%3Aci)
 
 Go library for accessing container images with their associated objects and
 typed metadata.
 
+## Experimental :test_tube:
+
+This repository is considered **EXPERIMENTAL** and under active development
+until further notice. It is subject to non-backward compatible changes or
+removal in any future version.
+
 ## Rationale
 
 Image authors are increasingly distributing associated metadata and artifacts
 alongside their images, such as OCI annotations, SLSA Provenance, SBOMs,
-signatures, and more. The exact method of storage can differ across the ecosystem,
-making this information difficult to consume.
+signatures, and more. The exact method of storage can differ across the
+ecosystem, making this information difficult to consume.
 
 This library provides a unified interface for accessing this metadata and
 ensuring that it can be consumed consistently.
 
+## Support
+
+This library supports pulling metadata from the following formats:
+
+- [BuildKit attestations](https://github.com/moby/buildkit/blob/master/docs/attestations/attestation-storage.md)
+
 ## Usage
 
 go-imageinspect is intended to be used as a library. However, for development