ko_KR/HOWTO: Convert to ReST notation

This commit applies commit 022e04d6 ("Documentation/HOWTO: convert
to ReST notation") to Korean translation and fix a trivial ReST build
failure problem.
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>