Let Japanese translation of howto.rst in the language drop-down list
by moving it to the expected place.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Tsugikazu Shibata <shibata@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <b175c52f-34ee-4753-b172-e57fee6fcc30@gmail.com>