docs: end of life

README.md

 # remoteuserssl-simplesamlphp-module
 
+![maintenance status: unmaintained](https://img.shields.io/maintenance/end%20of%20life/2021)
+
+This project is not maintained anymore, which means it does not receive any Security patches or bug fixes. Check out [SATOSA](https://github.com/IdentityPython/SATOSA) instead.
+
+## Description
+
 SimpleSAMLphp module for getting user identity from REMOTE_USER or SSL_CLIENT_S_CERT variables
 
-See docs/RemoteUserSSL.md for more information.
+See [docs/RemoteUserSSL.md](./docs/RemoteUserSSL.md) for more information.