docs(README): add info

Author: thomasleplus

README.md

@@ -76,3 +76,19 @@ The following checks were performed on each of these signatures:
 ```
 
 For instructions on how to install `cosign`, please read this [documentation](https://docs.sigstore.dev/cosign/system_config/installation/).
+
+## 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.