changelog: also monitor `00changelog.n` when applicable (issue6554)
This let the locarepo's file cache detect outdated nodemap docket and reload the
changelog after `localrepo.invalidate` when applicable.
Differential Revision: https://phab.mercurial-scm.org/D11482
#require docutils gettext $ $TESTDIR/check-gendoc zh_TW checking for parse errors