Add option get teams.yml from different repo

[andyantrim]

👋 Firstly, this is an awesome action, which I've found useful in auto-tagging some repos, let me explain the background for this PR :)

Background
Tagging a team name based on membership is something pretty useful for big organizations/communities etc however teams mostly span across several repos, and we don't want to duplicate the YAML file and maintain two versions of it.

What's changed

1. Optional argument teams-repo which points to another repository of the user/organization to store the YAML file
2. Default behavior will still pull from the current repository if this is not supplied
3. If this is supplied, we take the latest YAML from main (maybe this can be overwritten too?)

Let me know what you think, and sorry for the mess of the code, I'm not much of a typescripter :D

[JulienKode]

This totally makes sense @andyantrim, this is a great idea thanks 😊

Thanks for your contribution 😊

To be honest I do not know how to edit a branch from someone that created a PR from a fork, I've created this PR's #178