Add 'Mustache Basics' section.

Convert to handlebars, copy edit from following Sources:
http://mustache.github.io/mustache.5.html (mustache is MIT licensed, thanks Chris)
https://github.com/ractivejs/ractive/issues/98
https://github.com/ractivejs/ractive/pull/662
Merge pull request #109 from mikemaccana/master

Add 'Mustache Basics' section.