Update README.md

[ci skip]

Author: pllim

README.md

@@ -1,5 +1,6 @@
-This repository contains the Astropy web site (primary URL http://www.astropy.org).
-
-In a previous version of this web site (on the [old_site branch](https://github.com/astropy/astropy.github.com/tree/old_site)), this repository held the build for the site, but the content was generated from the [astropy-website repository](https://github.com/astropy/astropy-website).  That repo is no longer active, and issues with the astropy web site should now be reported in *this* repository.
+[![docs](https://app.readthedocs.org/projects/astropy-org/badge/?version=latest)](https://astropy-org.readthedocs.io/en/latest/)
 
+This repository contains the Astropy web site (primary URL https://astropy.org).
 
+> [!NOTE]
+> In a previous version of this web site (on the [old_site branch](https://github.com/astropy/astropy.org/tree/old_site)), this repository held the build for the site, but the content was generated from the [astropy-website repository](https://github.com/astropy/astropy-website).  That repo is no longer active, and issues with the Astropy web site should now be reported in *this* repository.