chore: add maintainer

[jdhoffa]

Even though this is a "relatively" small repository, we do plan to use it in production, so it needs a maintainer.
@AlexAxthelm @MonikaFu thoughts here?

I don't think it should be @cjyetman since he likely won't be working much on this project.

[AlexAxthelm]

probably me. I'll add a PR.