Add basic Dockerfile for building fixed version of Taky from tag

[Matthew-Beckett]

This PR adds a Dockerfile to the project which can build Taky from source based on a GitHub tag. This can be expanded later, and I will look to also add a GitHub build and push action on tags.

[jwarwick-bry]

If anyone ever comes back to this, I sent a handful of enhancements for this PR back up through Mr. Beckett's fork, but never heard anything from him. I would suggest having a look at that ( https://github.com/Matthew-Beckett/taky/pull/1 ) as something to stack on top of this.