Add ability to build Joystick as a static site

Fairly straightforward, just need to enforce some light conventions. Could do something as simple as:

joystick build -t static

That would spit out a directory of HTML, CSS, and JavaScript files built and ready to upload to a server or CDN. Could also tie this into Joystick Deploy so you have the option of pushing to a static bucket somewhere.

This should also work with Push. Ideally you could do joystick push static and it would prompt you to choose a destination (either an IP, S3 bucket, etc).

Not sure this is as easy as it seems. Hypothetically, yes, but you'd have to hit every route in the app, generate the HTML/CSS/JavaScript, and assume that the data it's fetching is public (i.e., no user required).

I may say table this for now as it's not really the use case for Joystick, even if it could work.