docs: def add_to_rc(self, content):
          """
          add content to the rc script.
          """
          if not self.rewrite_config:
              raise DirectoryException("Error! Directory was not intialized w/ rewrite_config.")
          if not self.rc_file:
              self.rc_path, self.rc_file = self.__get_rc_handle(self.root_dir)
          self.rc_file.write(content + '\n')