Add the Dockerfile to project root

[bbros-dev]

We never run containers without reviewing the Dockerfile.
We can't find the Dockerfile and this is blocking any further use.

[senare]

I don't disagree !

But there is always => https://hub.docker.com/layers/hieven/terraform-visual-cli/0.1.0-0.12.29/images/sha256-d7751c9a301f4064f344fe440ece149cea1752de9675a6f2bf2787db0e5a736c?context=explore

[bbros-dev]

Thanks for the workaround. Auditors wouldn't accept just that, but would also want to see the Dockerfile - verifying that when it is run they get the same result as in the link.