code: def write_contribs(def_dict_list: Dict[str, List[str]]) -> None:
      
      file_str = ''  # type: str
      note = '# Contributors\nCLTK Core authors, ordered alphabetically by first name\n\n'  # type: str  # pylint: disable=line-too-long
      file_str += note
      for contrib in def_dict_list:
          file_str += '## ' + contrib + '\n'
          for module in def_dict_list[contrib]:
              file_str += '* ' + module + '\n'
          file_str += '\n'
      file_name = 'contributors.md'  # type: str
      with open(file_name, 'w') as file_open:  # type: IO
          file_open.write(file_str)
      logger.info('Wrote contribs file at "%s".', file_name)
docs: Write to file, in current dir, 'contributors.md'.