docs: def commit_msg_hook(argv):
      """Hook: for checking commit message (prevent commit)."""
      with open(argv[1], "r", "utf-8") as fh:
          message = "\n".join(filter(lambda x: not x.startswith("#"),
                                     fh.readlines()))
      options = {"allow_empty": True}
  
      if not _check_message(message, options):
          click.echo(
              "Aborting commit due to commit message errors (override with "
              "'git commit --no-verify').", file=sys.stderr)
          raise click.Abort
      return 0