The current process in CONTRIBUTING.md is pretty much "contact us":

5609071

@jgillula suggests:

One thing we might want to add is a section with more detail about how
to be a ruleset maintainer--what to look for, what to test, etc. I think
even just a couple sentences that refer to the testing and style
sections saying "refer to these sections" would be useful.

We should also encourage people from different regions of the world and non-English speakers to become ruleset maintainers, who can judge if pages are being served correctly in the transition to HTTPS.