Add JSDOC Preview

@jmeas brought up a good point in channel that we've heard from almost everyone working on the api @joshbedo, @jdaudier, @moimikey... It's not obvious how to preview the api on the website! 

This is crazy because unless you can see how it looks, it's hard to see if the documentation you just wrote is right.
Two suggestions:

– Separate out the one-time-only steps from the every-time steps. I imagine you don't clone the repo everytime you want to preview the API :)

– Describe each of these steps in English, *in addition* to showing the code.