Update Jekyll Template Structure

Default Jekyll structure was designed for pre-flex layout hacks. New
site will utilize html5 flex, and html5 semantic elements.

modified:
* (_source/_includes/footer.html)
* (_source/_includes/head.html)
* (_source/_includes/header.)
* (_source/_layouts/default.html)
* (_config.yml)
Merge commit 'c021f12' into release-1.0.0

[fix] 2x shame on me. git commit ammend.

Git commit ammend should be avoided, maybe till I have a better grasp.