doc update
reorganized includes. piddly stuff
More automated critical css build.

Use grunt-contrib-connect to elimate need to manually run jekyll.
Generate critical css in `grunt prod` task by building the site
in dev mode, running criticalcss target, then rebuilding the site
in production mode.
Removed generated critical css from version control.

No need for this anymore with the improved build process.
Comments. Removed unused shell target