Add "Teams" support for alerts

[tshrinivasan]

Thanks for the wonderful work.

Please add Microsoft Teams for alerts.

Here are few tutorials on how to do the alerts for teams in python.
https://pythoncircle.com/post/725/how-to-post-messages-to-microsoft-teams-channel-using-python/
https://www.hull1.com/scriptit/2020/08/18/python-to-teams.html

This will help a lot.

[jamesoff]

Thanks! I'll take a look sometime, but I don't use Teams myself. I do accept PRs if you wanted to have a go at implementing it yourself :)

[mikbro2021]

You can post to a channel in Teams using it's email address so the standard email alerter would work