Add label notifier workflow?

Created by: Joelkw

I prefer to get notified when someone adds a new issue with the team/web label on it rather than check across various repos or label-filtered searches to make sure I'm aware of new stuff.

I didn't know of another way to easily keep eyes on all team/web issues (if there's an obvious one I'm missing that's native) but I found this github action and it passed a couple of quick tests I ran here. Once/if we add this, I'll post about it in slack so folks know it's a tool available.

(The way it works is just by tagging in anyone it's set to mention in a github bot comment on the issue, so it's clear someone was notified.)