doc: cncf onboarding of oauth2-proxy

Added sections for Code of Conduct, License, and Trademarks in README.

Signed-off-by: Jan Larwig <jan@larwig.com>

Author: tuunit

README.md

@@ -39,3 +39,23 @@ Note:
 We utilize cosign to sign and verify artifacts with the KEYLESS mode. To learn
 more about how keyless signing is done, visit the official documentation about 
 [Keyless Signatures](https://docs.sigstore.dev/cosign/signing/overview/#the-signing-witnessing-and-verifying-process).
+
+
+## Code of Conduct
+Participation in the OAuth2-Proxy project is governed by the [CNCF Code of Conduct](https://github.com/oauth2-proxy/oauth2-proxy/tree/master/CODE_OF_CONDUCT.md).
+
+## License
+
+OAuth2-Proxy is distributed under [The MIT License](https://github.com/oauth2-proxy/oauth2-proxy/tree/master/LICENSE).
+
+[![FOSSA Status](https://app.fossa.com/api/projects/git%2Bgithub.com%2Foauth2-proxy%2Foauth2-proxy.svg?type=large&issueType=license)](https://app.fossa.com/projects/git%2Bgithub.com%2Foauth2-proxy%2Foauth2-proxy?ref=badge_large&issueType=license)
+
+The OAuth2-Proxy helm chart is distributed under [Apache License 2.0](https://github.com/oauth2-proxy/manifests/tree/main/LICENSE).
+
+## Trademarks
+
+OAuth2-Proxy is a [Cloud Native Computing Foundation](https://cncf.io) Sandbox project.
+
+![CNCF](https://www.cncf.io/wp-content/uploads/2023/04/cncf-main-site-logo.svg)
+
+The Linux Foundation® (TLF) has registered trademarks and uses trademarks. For a list of TLF trademarks, see [Trademark Usage](https://www.linuxfoundation.org/legal/trademark-usage).