Sites in private beta (current example – screenshot for when it reaches public beta) have a yellow banner on all pages making users aware of the Meta site:
got a question about the site itself? proofassistants.meta is the place to talk about things like what questions are appropriate, what tags we should use, etc.
I think it looks better if the first sentence uses 'proper' grammar and is in sentence case, and the link title is changed to the name of the meta site:
Do you have a question about the site itself? Proof Assistants Meta is the place to talk about things like what questions are appropriate, what tags we should use, etc.