CNCF Graduation Checklist

*Description*:
>Describe the issue.

Envoy Gateway is a sub project of Envoy, which is a graduated CNCF project. This is similar to Gateway API which a sub project of Kubernetes, which is a graduated project.

Due to this, Envoy Gateway is not required to go through the formal CNCF graduation criteria, but would be great to check off the items in the Graduation Checklist and highlight them here or the website to build more trust amongst end users

* Incubation Checklist https://github.com/cncf/toc/blob/main/.github/ISSUE_TEMPLATE/template-incubation-application.md
* Graduated Checklist https://github.com/cncf/toc/blob/main/.github/ISSUE_TEMPLATE/template-graduation-application.md

[optional *Relevant Links*:]
>Any extra documentation required to understand the issue.