GitHub has a wiki feature that can be enabled on a repo. This can be an easy solution for documenting contributions, plans, community info and / or documentation.
Google's stance is wikis should restrict contributions to collaborators who have edit access to the repository.
IMPORTANT: If you would like your project to have a public wiki, please read the policy below and follow the steps.
Public wiki policy
Public wikis on GitHub allow any GitHub account holder to edit a wiki without review. This introduces a burden on the repo owners to ensure no malicious parties alter the contents in unintended ways.
For this reason, the default configuration for repos is to restrict editing to users with push access to the repo. This restriction will be managed by the OSPO engineering team.
There are scenarios where a public wiki is desirable, especially if you have a community that is willing to maintain the wiki on a regular basis. In this scenario you can enable public wiki editing by following these steps:
Add your repo to the allowlist in //piper/.../public-wiki-allowlist.textproto
Once the CL is approved from the previous step, go to your repo settings on GitHub and uncheck “Restrict editing to users in teams with push access only”. More info can be found on GitHub's docs.