Should support -chdir flag

[hileef]

At this time, this friendly tool appears to expect to find the terraform module in the current working directory in order to select a terraform version. In some cases (esp. w.r.t. scripting), it can be beneficial to indicate a directory a given process is expected to changes it working directory to ; in the case of terraform, that would be via the -chdir flag.

It would be awesome if this tool supported that flag by using it as the directory to search its required version at (when provided of course, falling back to its current behaviour) 🙏

If no one is against it I'll attempt a tentative implementation in the near future. 🙂