Include badge for the docs

README.md

@@ -2,9 +2,11 @@
 
 [![Tests][badge-tests]][tests]
 [![Coverage][badge-coverage]][coverage]
+[![Documentation][badge-docs]][documentation]
 
 [badge-tests]: https://img.shields.io/github/actions/workflow/status/quadbio/cell-annotator/test.yaml?branch=main
 [badge-coverage]: https://codecov.io/gh/quadbio/cell-annotator/branch/main/graph/badge.svg
+[badge-docs]: https://img.shields.io/readthedocs/cell-annotator
 
 A tool to annotate cell types based on marker genes using OpenAI models. Inspired by [Hou et al., Nature Methods 2024](https://www.nature.com/articles/s41592-024-02235-4) and [https://github.com/VPetukhov/GPTCellAnnotator](https://github.com/VPetukhov/GPTCellAnnotator).
 
@@ -40,3 +42,4 @@ If you found a bug, please use the [issue tracker][].
 [issue tracker]: https://github.com/quadbio/cell-annotator/issues
 [tests]: https://github.com/quadbio/cell-annotator/actions/workflows/test.yaml
 [coverage]: https://codecov.io/gh/quadbio/cell-annotator
+[documentation]: https://cell-annotator.readthedocs.io