Migration to Jekyll for the website

This PR migrates the website to Jekyll.

I am running a preview of the new Jekyll site on GitHub Pages here: [http://stephenhowells.github.io/Vaprobash/](http://stephenhowells.github.io/Vaprobash/)

It adds nice code highlighting and allows content to be written in GitHub flavored Markdown. Also, there is now includes for the top-nav, sidebar, header, and footer.

This migration allows us to move on to other aspects such as more in-depth documentation and improving the design.