This commit adds a Markdown tree-processor extension that renders
multi-line code blocks that are nested inside lists with the
formatting. Note that the code block could be nested inside multiple
list levels and would still get rendered correctly.
Tim: This fixes the need for unpleasant workarounds like
f5bfa4e793 and makes nested code blocks
in our documentation look exactly how users would expect them to.
Eeshan Garg