Expand tutorial and current reference into blockstack.js Developer Guide

[moxiegirl]

@friedger suggested we build out a similar guide (simpler of course) https://developer.android.com/guide/

Currently, we have:

• tutorial (hello world)
• reference
• three more sophisticated but undocumented examples

[friedger]

@moxiegirl I added some paragraphs in the README (See #123) Should this stay there or go somewhere else? Should we generate documentation from the example codes? So that we can maintain the code only in the source folder?

[moxiegirl]

@friedger Well, when it comes to API reference it makes sense to generate it from the source code. Tutorials are a bit problematic, depends on the tool of course. Do you have one in mind?

[moxiegirl]

Issue moved to blockstack/docs.blockstack #91 via ZenHub