Docs/admin-guide/mm/damon/usage: describe the rules of sysfs region directories

Docs/admin-guide/mm/damon/usage: describe the rules of sysfs region directories

Patch series "Docs/admin-buide/mm/damon/usage: minor fixes".

DAMON usage document contains an unclear description and a wrong usage
example.  This patchset fixes the two minor problems.

This patch (of 2):

Target region directories of DAMON sysfs interface should contain no
overlap and sorted by the address, but not clearly documented.  Actually,
a user had an issue[1] due to the poor documentation.  Add clear
description of it on the usage document.

[1] https://lore.kernel.org/damon/CAEZ6=UNUcH2BvJj++OrT=XQLdkidU79wmCO=tantSOB36pPNTg@mail.gmail.com/

Link: https://lkml.kernel.org/r/20221024174619.15600-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20221024174619.15600-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Vinicius Petrucci <vpetrucci@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>