[doc] Improved doc string for logging.py function
[doc] Improved doc string for logging.py function

Extended doc strings for logging.py functions such as error, exception,
stdout, log, critical and debug.

Bug: T85271
Change-Id: I265a5258d711a6e038b1974e4f1cf29fd5c0f650

wikimedia/pywikibot-core,wikimedia/pywikibot-core