added setup_logging() method in splunklib for logging and updated README.md files

[akaila-splunk]

• Used module-specific logger in splunklib code instead of root logger
• Added new setup_logging() method in splunklib to set logging level, log format(optional) and date format(optional)
• Updated REAME.md file with details of setup_logging() method
• Updated searchcommands_app/README.md file with some details of logging.conf file and how to see debug logs
• Here is an example of log message,

Before code change:
	DEBUG:root:Log message
After code change:
	2022-03-03 19:12:58 India Standard Time, Level=DEBUG, Pid=11120, Logger=splunklib.binding, File=binding.py, Line=72, Log message

[fantavlik]

Well done! Thanks for walking us through the design along the way on our weekly syncs