Add the initial documentation files.

All documentation and content is written using Markdown, and Jekyll is used to generate the website from these sources.  When ready, the generated output will be pushed to GitHub Pages.
Updated to the following:

> When SPF sends a request to the server, it appends a configurable
> identifier to the URL so that you can properly handle the request.
> (By default, this will be `?spf=navigate`.)