Keep inline Markdown code styles consistent between edit and render.

Review Request #11594 — Created April 12, 2021 and submitted — Latest diff uploaded

Review Board

A pet peeve of mine for years has been that inline code would style
differently between CodeMirror (edit mode) and rendered Markdown. The
edit mode style was just a sort of metalic purple text. The rendered
style was red, with a faint background and border.

This change makes the styles consistent between the two, choosing the
rendered mode. There's now a 1-to-1 pixel mapping between the two, with
the exception that in edit mode, the backticks are visible.

Tested in Chrome and Firefox. Swapped between edit and render modes, and
saw they were consistent.