Add support for MS Teams

[mlissner]

I can never tell if these corporate tools are worth doing. We don't hear demand for it, but it could be a chicken/egg issue.

Anyway, @anseljh suggested this, so I figured I'd put it on the backlog, though I'm filing it in the "someday" milestone until we hear from at least one org that'd use it.

[mlissner]

This is a post by a skilled Django dev that dealt with MS Teams: https://adamj.eu/tech/2024/09/04/django-microsoft-teams-bot/

I think he does consulting too. It'd be pretty cool to get him involved in this, but if nothing else, we can learn from this post when we get around to this.