Merge topic 'doc-improvements'

d4d1f85297 Help: Move a note about arguments and genexes into include file
968224484f Help: Drop unused `PROPERTY_GENEX` replace from `prop_tgt/INTERFACE_*` files
65457e4fae Help: Add _See Also_ sections to related CMake commands
c86ec79d07 Help: Use direct refs to genexes instead of ``$<GENEX-NAME>``
8c6274326d Help: Use CMake highlighting for command synopsis
c356a94512 Help: Use monospaced font for a genex name in a section title
f98c8707f4 Help: Use `code-block:: cmake` instead of `::` for sub-commands descriptions
2ba351ca4f Help: ``CMake`` → CMake
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !7873