Docs/admin-guide/mm/damon/usage: update for young page type DAMOS filter

Update DAMON usage document for the newly added DAMOS filter type, 'young
page'.

Link: https://lkml.kernel.org/r/20240426195247.100306-7-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Cc: Honggyu Kim <honggyu.kim@sk.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Documentation/admin-guide/mm/damon/usage.rst

@@ -410,19 +410,19 @@ in the numeric order.
 
 Each filter directory contains six files, namely ``type``, ``matcing``,
 ``memcg_path``, ``addr_start``, ``addr_end``, and ``target_idx``.  To ``type``
-file, you can write one of four special keywords: ``anon`` for anonymous pages,
-``memcg`` for specific memory cgroup, ``addr`` for specific address range (an
-open-ended interval), or ``target`` for specific DAMON monitoring target
-filtering.  In case of the memory cgroup filtering, you can specify the memory
-cgroup of the interest by writing the path of the memory cgroup from the
-cgroups mount point to ``memcg_path`` file.  In case of the address range
-filtering, you can specify the start and end address of the range to
-``addr_start`` and ``addr_end`` files, respectively.  For the DAMON monitoring
-target filtering, you can specify the index of the target between the list of
-the DAMON context's monitoring targets list to ``target_idx`` file.  You can
-write ``Y`` or ``N`` to ``matching`` file to filter out pages that does or does
-not match to the type, respectively.  Then, the scheme's action will not be
-applied to the pages that specified to be filtered out.
+file, you can write one of five special keywords: ``anon`` for anonymous pages,
+``memcg`` for specific memory cgroup, ``young`` for young pages, ``addr`` for
+specific address range (an open-ended interval), or ``target`` for specific
+DAMON monitoring target filtering.  In case of the memory cgroup filtering, you
+can specify the memory cgroup of the interest by writing the path of the memory
+cgroup from the cgroups mount point to ``memcg_path`` file.  In case of the
+address range filtering, you can specify the start and end address of the range
+to ``addr_start`` and ``addr_end`` files, respectively.  For the DAMON
+monitoring target filtering, you can specify the index of the target between
+the list of the DAMON context's monitoring targets list to ``target_idx`` file.
+You can write ``Y`` or ``N`` to ``matching`` file to filter out pages that does
+or does not match to the type, respectively.  Then, the scheme's action will
+not be applied to the pages that specified to be filtered out.
 
 For example, below restricts a DAMOS action to be applied to only non-anonymous
 pages of all memory cgroups except ``/having_care_already``.::