Add About link to the navs
Remove home link from the navs

While I think the home link is nice, the site title accomplishes the same
purpose. This trims down the nav to have one less item, which is nice as the
list of nav items grows.
Add jemoji support
Add Gemfile w/ github-pages gem

When developing the site, make it easy to install the required dependencies for
running the site.

Ignore the Gemfile.lock, as the versions of gems should not really matter at
this time. The latest version of the github-pages gem should suffice.