Aidan/datasource group

[artificial-aidan]

Adds a datasource for group. Along with a few tests.

I made the organization a variable that defaults to barnabyshearer so that I could override it when writing tests. I can remove this if needed for upstreaming.

[dannysauer]

PRs from well over a year ago going unattended... Seems as if perhaps this provider is just dead.

[artificial-aidan]

I published it here: https://registry.terraform.io/providers/artificialinc/dockerhub/latest

No guarantees on updates or continuing maintenance. But if you just need the group datasource it works.

[dannysauer]

Actually I need the privacy change function. 😂