docs(README): add info

Author: thomasleplus

README.md

@@ -320,3 +320,19 @@ tests that can be run online at
 <https://op.certification.openid.net:60000> and
 <https://rp.certification.openid.net:8080>, with the corresponding
 [source code](https://github.com/openid-certification/oidctest).
+
+## Contributing
+
+Please read [CONTRIBUTING.md](CONTRIBUTING.md) for details on our code of conduct and the process for submitting pull requests.
+
+## Security
+
+Please read [SECURITY.md](SECURITY.md) for details on our security policy and how to report security vulnerabilities.
+
+## Code of Conduct
+
+Please read [CODE_OF_CONDUCT.md](CODE_OF_CONDUCT.md) for details on our code of conduct.
+
+## License
+
+This project is licensed under the terms of the [LICENSE](LICENSE) file.