Docs/damon: update titles and brief introductions to explain DAMOS

DAMON was initially developed only for data access monitoring, and then
extended for not only access monitoring but also access-aware system
operations (DAMOS). But the documents have old titles and brief
introductions for only the monitoring part. Update the titles and the
brief introductions to explain DAMOS part together.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: SeongJae Park <[e-mail]>
Cc: Brendan Higgins <[e-mail]>
Cc: David Gow <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

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

···
 .. SPDX-License-Identifier: GPL-2.0
 
-==========================
-DAMON: Data Access MONitor
-==========================
+================================================================
+DAMON: Data Access MONitoring and Access-aware System Operations
+================================================================
 
-:doc:`DAMON </mm/damon/index>` allows light-weight data access monitoring.
-Using DAMON, users can analyze the memory access patterns of their systems and
-optimize those.
+:doc:`DAMON </mm/damon/index>` is a Linux kernel subsystem for efficient data
+access monitoring and access-aware system operations.
 
 .. toctree::
    :maxdepth: 2

Documentation/mm/damon/index.rst

···
 .. SPDX-License-Identifier: GPL-2.0
 
-==========================
-DAMON: Data Access MONitor
-==========================
+================================================================
+DAMON: Data Access MONitoring and Access-aware System Operations
+================================================================
 
 DAMON is a Linux kernel subsystem that provides a framework for data access
 monitoring and the monitoring results based system operations.  The core