docs: def generate_authors(git_dir):
      """Create AUTHORS file using git commits."""
      authors = []
      emails = []
      git_log_cmd = ['git', 'log', '--format=%aN|%aE']
      tmp_authors = _run_shell_command(git_log_cmd, git_dir).split('\n')
      for author_str in tmp_authors:
          author, email = author_str.split('|')
          author = author.strip()
          email = email.strip()
          if author.lower() not in [x.lower() for x in authors]:
              if email.lower() not in [x.lower() for x in emails]:
                  authors.append(author)
                  emails.append(email)
      co_authors_raw = _run_shell_command(['git', 'log'], git_dir)
      co_authors = re.findall('Co-authored-by:.+', co_authors_raw,
                              re.MULTILINE)
      co_authors = [signed.split(":", 1)[1].strip().split('<')
                    for signed in co_authors if signed]
      for author_str in co_authors:
          author, email = author_str.split('<')
          author = author.strip()
          email = email[:-1].strip()
          if author.lower() not in [x.lower() for x in authors]:
              if email.lower() not in [x.lower() for x in emails]:
                  authors.append(author)
                  emails.append(email)
      authors = sorted(set(authors))
      return authors