docs: def valid_config_exists(config_path=CONFIG_PATH):
      """Verify that a valid config file exists.
  
      Args:
          config_path (str): Path to the config file.
  
      Returns:
          boolean: True if there is a valid config file, false if not.
      """
      if os.path.isfile(config_path):
          try:
              config = read_config(config_path)
              check_config(config)
          except (ConfigurationError, IOError):
              return False
      else:
          return False
      return True