Add docs and GitHub Pages deployment automation

This adds the mkdocs file structure and some very basic documentation to get the ball rolling.

Also included is some automation with CircleCI to automatically deploy to GitHub Pages when a commit is made to the _version-1.0_ branch.  Eventually we'll change that to _master_.

Add docs by editing or adding to markdown in the docs directory.  Preview with `pip install mkdocs && mkdocs serve` from the root directory.  When a pull-request is accepted, CircleCI will deploy it to the live site.

Right now the site lives at [dustinfarris.com/ember-django-adapter](http://dustinfarris.com/ember-django-adapter/).  Apparently, GitHub picked up the CNAME from my primary user GitHub Pages site and extended it here.  I guess it can stay like that for now until/if we decide to purchase a domain.