Docs/mm/damon: recommend academic papers to read and/or cite

Kernel documentation is the most up-to-date and recommended resource for
DAMON.  It doesn't cover non-kernel part of the entire project[1], though.
Also it is not optimum for formal long-term citations.  Depending on
cases, DAMON academic papers[2,3] could be better to be read and cited. 
However, there is no clear guidance for those.  Add a paragraph for DAMON
academic papers on the kernel documentation for DAMON.

[1] https://damonitor.github.io
[2] https://dl.acm.org/doi/abs/10.1145/3366626.3368125
[3] https://dl.acm.org/doi/abs/10.1145/3502181.353146

Link: https://lkml.kernel.org/r/20241101203557.55210-1-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: sjp38

Documentation/mm/damon/index.rst

@@ -37,3 +37,9 @@ with no code but simple configurations.
 
 To utilize and control DAMON from the user-space, please refer to the
 administration :doc:`guide </admin-guide/mm/damon/index>`.
+
+If you prefer academic papers for reading and citations, please use the papers
+from `HPDC'22 <https://dl.acm.org/doi/abs/10.1145/3502181.3531466>`_ and
+`Middleware19 Industry <https://dl.acm.org/doi/abs/10.1145/3366626.3368125>`_ .
+Note that those cover DAMON implementations in Linux v5.16 and v5.15,
+respectively.