Clarify description for rcFile

[blackHatMonkey]

Hi I recently began to get the following error:

Error: Traceback (most recent call last):
  File "/usr/local/bin/pylint", line 11, in <module>
    sys.exit(run_pylint())
  File "/usr/local/lib/python2.7/dist-packages/pylint/__init__.py", line 17, in run_pylint
    Run(sys.argv[1:])
  File "/usr/local/lib/python2.7/dist-packages/pylint/lint.py", line 1287, in __init__
    linter.read_config_file()
  File "/usr/local/lib/python2.7/dist-packages/pylint/config.py", line 636, in read_config_file
    with io.open(config_file, 'r', encoding='utf_8_sig') as fp:
IOError: [Errno 21] Is a directory: '/home/blackhatmonkey/workspace'
    at /home/blackhatmonkey/.atom/packages/linter-pylint/lib/main.js:130:19

I was wondering if you could help me figure out the problem.