update readme

README.md

@@ -1,11 +1,8 @@
 espaloma: **E**xtensible **S**urrogate **P**otenti**al** **O**ptimized by **M**essage-passing **A**lgorithms 🍹
 ==============================
 [//]: # (Badges)
-[![CI](https://github.com/choderalab/espaloma/actions/workflows/CI.yaml/badge.svg?branch=master)](https://github.com/choderalab/espaloma/actions/workflows/CI.yaml)
-[![Total alerts](https://img.shields.io/lgtm/alerts/g/choderalab/espaloma.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/choderalab/espaloma/alerts/)
-[![Language grade: Python](https://img.shields.io/lgtm/grade/python/g/choderalab/espaloma.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/choderalab/espaloma/context:python)
-[![docs stable](https://img.shields.io/badge/docs-stable-5077AB.svg?logo=read%20the%20docs)](https://espaloma.wangyq.net/)
-
+[![CI](https://github.com/choderalab/espaloma/actions/workflows/CI.yaml/badge.svg?branch=main)](https://github.com/choderalab/espaloma/actions/workflows/CI.yaml)
+[![Documentation Status](https://readthedocs.org/projects/espaloma/badge/?version=latest)](https://espaloma.readthedocs.io/en/latest/?badge=latest)
 
 Source code for [Wang Y, Fass J, and Chodera JD "End-to-End Differentiable Construction of Molecular Mechanics Force Fields."](https://arxiv.org/abs/2010.01196)