Changes documentation site back to using Jekyll instead of Assemble.

Assemble gained us nothing and it actually clouds the GitHub Pages repository more than Jekyll.

Plus, Jekyll is officially supported by GitHub, so that's always nice.

Fixes #23
Updates packages and bumps version number.
Updates documentation with new shortcode tag.

Fixes #29
Updates documentation to show id attribute use.

Fixes #23
Updates documentation to note automatic updates as a feature.

Fixes #31