docs: fix docs badge

Author: gadomski

README.md

@@ -3,7 +3,7 @@
 [![CI](https://github.com/stac-utils/pystac-client/actions/workflows/continuous-integration.yml/badge.svg)](https://github.com/stac-utils/pystac-client/actions/workflows/continuous-integration.yml)
 [![Release](https://github.com/stac-utils/pystac-client/actions/workflows/release.yml/badge.svg)](https://github.com/stac-utils/pystac-client/actions/workflows/release.yml)
 [![PyPI version](https://badge.fury.io/py/pystac-client.svg)](https://badge.fury.io/py/pystac-client)
-[![Documentation](https://readthedocs.org/projects/pystac-client/badge/?version=latest)](https://pystac-client.readthedocs.io/en/latest/)
+[![Documentation](https://readthedocs.org/projects/pystac-client/badge/?version=stable)](https://pystac-client.readthedocs.io)
 [![codecov](https://codecov.io/gh/stac-utils/pystac-client/branch/main/graph/badge.svg)](https://codecov.io/gh/stac-utils/pystac-client)
 
 A Python client for working with [STAC](https://stacspec.org/) Catalogs and APIs.