Expand the 'Variables' page so that it links to the two-way variables
page from within the body of text. Having the link in only the side-bar
was too easy to miss.
Move the "Custom Job Types" expandable section to its own, normal
section.
The expandable sections in the docs aren't that clear, visually. It's
easy to miss that they can be expanded. This was the only use of this
feature.
