code: def add_rfile(self, name, help, required=True, default=None):
  		
  		if isinstance(default, str):
  			default = default.replace('$DATA_PATH ', self.directories.data_path + os.path.sep)
  			default = default.replace('$USER_DATA ', self.directories.user_data + os.path.sep)
  		self._options[name] = Option(name, 'rfile', help, required, default=default)
docs: Add a new option with a type of a readable file. This is the same
  		as the string option with the exception that the default value
  		will have the following variables replaced within it:
  			$USER_DATA The path to the users data directory
  			$DATA_PATH The path to the framework's data directory
  		This will NOT check that the file exists or is readable.
  
  		:param str name: The name of the option, how it will be referenced.
  		:param str help: The string returned as help to describe how the option is used.
  		:param bool required: Whether to require that this option be set or not.
  		:param str default: The default value for this option. If required is True and the user must specify it, set to anything but None.