feature: bot to ping a team upon issues creation in nodejs/help

[refack]

For example nodejs/help#592 has the proper format so in Includes:

• OS: Windows 7

This would ping @nodejs/help-windows

[addaleax]

I’m worried that this would create a lot of noise… most bug reports we get aren’t platform-specific, so it might be best to not just ping people because they filled out the issue template in a specific way.

Maybe pinging a specific group when a label gets added makes more sense (still quite noisy)…

[refack]

It should be a opt-in group @nodejs/help-windows not @nodejs/platform-windows. And that raises the question who does triage. If it's a contributor probably they know what to do or who to ping. I want to be more proactive in help but it's a very eclectic collection.