Vendor the css and refer to it instead

We were linking to `http://jashkenas.github.io/docco/resources/linear/docco.css` but that has changed a lot and the examples all look horrible now.  This should fix it.
The `api.docurium` file has a `github` field which we could use to determine whether the project is hosted on GitHub, so we could base some logic off of that, but I agree it's al going to be somewhat ugly no matter what.

If we include `{{css}}` somwhere and pass in the contents of the CSS file, it should work, even if it means larger file sizes.