Investigate if all GitHub teams can be made public

Created by: fredg02

In the spirit of being open and transparent we should check if all GitHub teams can be made public.

@chrisguindon mentioned that there was (or still is?) an issue with public teams that allowed members to add other users or create nested teams. There might have been/be other issues.

I did a quick test and was not able to add more users or create nested teams to a public team, but more testing needs to be done.

For now this is a nice-to-have feature.