General Kramdown Syntax
Jekyll uses kramdown, which is a superset of Markdown. General kramdown syntax can be found here:
https://kramdown.gettalong.org/syntax.html
The page above contains all the gory details of Kramdown. The following sections are intended to get you up and running quickly.
Documentation Theme for Jekyll
We use the Documentation Theme for Jekyll. Information on how the theme works can be found as part of this documentation set (see upstream docs).