I am under the impression that any community member can raise and issue but the website wg should agree that this issue should be worked on.
I also don't think issue assignment is a thing and if an issue is not actively worked on (no open pr against the issue), it is avaliable for anyone to work on it without needing to be assigned.
I have often seen folks asking to be assigned to an issue, it not being clear that an issue is awaiting approval from the wg, and sometimes seen multiple folks raise PRs for the same issue.
I think having a reference to the website wg and some guidelines for contributing added to the readme would be useful here