Create a github workflow to import a repository to be managed by TF.

[tim-schilling]

As per #31 (comment), to onboard a repository, we need to run a command with a local terraform installation. To make it easier to maintain the organization we should look for a way to automate this with GHA or something similar (Remove the requirement to have a local terraform installation).

Design:
A github workflow which can be manually dispatched with an input of "repo-name".
AFTER a repo was transferred, trigger the import workflow with the repo-name to update tfstate.json in the repo.