[FEATURE] Traverse Sub Directories

[jseiser]

We use a large mono repo, and there are times when it would be nice to be able to update multiple states with the new templates in one go.

Currently we have to get into each dir, or use some bash-isms to loop through. Would be great, if you could tell tfgen to run in all subdirs, that contains a .tf file or something

[refl3ction]

That's a good one @jseiser , I will add it to the backlog. Thanks for sharing.