Prepare Overlay 1.2 Release Notes

[lornajane]

We'll need release notes (and probably a blog post) for the Overlay 1.2 release.

[lornajane]

@baywet FYI - I assigned myself but let me know if you'd rather write than review

[baywet]

@lornajane I'm currently on vacation qnd under the weather 🤒
Please go ahead, and if you haven't had a chance to do this one, I'll take it when I'm back