In our markdown style, we showed inline code in blue, and code blocks were

indented. This wasn't great for readability, and the world has moved on. This

change mimics the Slack style for code blocks, which has started to percolate

out into the rest of the world (GitHub also shows code blocks with a grey

background these days).
While I was in here I noticed that a few things used a "pre-wrap" macro which

wasn't defined. I've added a definition for that.

Created a description with an inline code span, a code block with syntax

highlighting, and a code block without. Saw that everything looked very nice.