move contributing and collaboration guide to .github

[bjohansebas]

This is part of adding the documentation that can be inherited from this repository.

Port of #18

See also expressjs/discussions#353

[bjohansebas]

cc: @expressjs/express-tc

[wesleytodd]

I dont like that added complexity of the admin repo. I was thinking we should make the .github repo the source for all we can. Honestly the name of the repo doesn't really matter as long as the docs are in the right place and the links are all correct.

My main concern with this current form is that we dont have a good concept in here of the difference between contributing to express vs all the other packages. I think we should keep this in a branch and open PRs against it here until we are satisfied. This whole consolidation effort was one of the main things I wanted to do soon, so let me just leave this comment here and circle back in a week or so.

[ctcpip]

Agree with Wes. Frankly, we have a backlog of updating the contributing guide, as well as the security policy -- something we delayed doing until after the audit was complete and we were in 2025.

[bjohansebas]

see also expressjs/discussions#353

cc: @expressjs/express-tc

[wesleytodd]

Anything to pull this out of the express repo is good, but I do think the governence docs are not supported by GH to show in every repo, and also they apply for us to all three orgs, so we may be better off with that one in discussions than here.

[bjohansebas]

I do think the governence docs are not supported by GH to show in every repo

Yeah, even opening it on GitHub so they support this, since they show it as if they were going to do it.

https://github.com/orgs/community/discussions/155344

[wesleytodd]

I am making a few edits to hopefully get this landed.