Put documentation status badge in readme

README.md

@@ -3,6 +3,7 @@
 [![Tests](https://github.com/dtu-qmcm/enzax/actions/workflows/run_tests.yml/badge.svg)](https://github.com/dtu-qmcm/enzax/actions/workflows/run_tests.yml)
 [![Project Status: WIP – Initial development is in progress, but there has not yet been a stable, usable release suitable for the public.](https://www.repostatus.org/badges/latest/wip.svg)](https://www.repostatus.org/#wip)
 [![Supported Python versions: 3.12 and newer](https://img.shields.io/badge/python->=3.12-blue.svg)](https://www.python.org/)
+[![Documentation Status](https://readthedocs.org/projects/enzax/badge/?version=latest)](https://enzax.readthedocs.io/en/latest/?badge=latest)
 
 Enzax is a library of automatically differentiable equations and solvers for modelling networks of enzyme-catalysed reactions, written in [JAX](https://jax.readthedocs.io/en/latest/).