pkg/md: Don't skip with regexp match.
pkg/md: Don't skip with regexp match.

Indented code blocks and link reference definitions are used a lot in other
sections, and they used to be skipped by matching the markdown with regexp
patterns. However, this has some false positives, so list the individual example
IDs instead.

elves/elvish,elves/elvish,elves/elvish,elves/elvish,elves/elvish