Add link to README.

Author: hsluoyz

README.md

@@ -9,6 +9,10 @@ jCasbin
 [![Release](https://img.shields.io/github/release/casbin/jcasbin.svg)](https://github.com/casbin/jcasbin/releases/latest)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/casbin/lobby)
 
+💖 [**Looking for an open-source identity and access management solution like Okta, Auth0, Keycloak ? Learn more about: Casdoor**](https://casdoor.org/)
+
+<a href="https://casdoor.org/"><img src="https://user-images.githubusercontent.com/3787410/147868267-6ac74908-5654-4f9c-ac79-8852af9ff925.png" alt="casdoor" style="width: 50%; height: 50%"/></a>
+
 **News**: still worry about how to write the correct jCasbin policy? ``Casbin online editor`` is coming to help! Try it at: http://casbin.org/editor/
 
 ![casbin Logo](casbin-logo.png)