Extra features

[mattdesl]

I have three features I miss from Beefy:

• auto portfinding instead of erroring out if 9966 is taken
• an --open command to launch the URL in your browser
• a --dir to set the base for the entries (from path) and the serving directory (i.e. for image paths)

I've already implemented these in my own little tool. Basically wondering whether you'd be interested in having these PR'd to wzrd CLI (but not the API itself). Or, whether you'd prefer these things to just go in another module.

[max-mapper]

portfinding and --dir are fine, but I am weary of the --open one because it's a tricky cross platform problem. How did you implement that?

[mattdesl]

Could use open or opn but I agree it's tricky and a bit more prone to error.