[doc] Note that pywikibot/compat is deprecated for 5 years
[doc] Note that pywikibot/compat is deprecated for 5 years

- catlib is deprecated since December 2014
- query is deprecated since June 2012
- userlib  is deprecated since December 2014

This should be noted in the DIRECTORIES.rst

Change-Id: Iaa484b2df387d2b359b756777f6cb3bf81ec5c19

PersianWikipedia/pywikibot-core,wikimedia/pywikibot-core,wikimedia/pywikibot-core