Documentation: can I specify a different Dockerfile?

[LourensVeen]

I need to build different Docker images within the same build context. Docker supports that by letting you specify a different Dockerfile than the default context/Dockerfile. Does boatswain support that?

The README says in a comment in the example that the key context gives the "path to the Dockerfile" which is maybe not the best phrasing. Complete documentation for the boatswain configuration file format would be nice...