docs: def abook2vcf():
      """Command line tool to convert from Abook to vCard"""
      from argparse import ArgumentParser, FileType
      from os.path import expanduser
      from sys import stdout
  
      parser = ArgumentParser(description='Converter from Abook to vCard syntax.')
      parser.add_argument('infile', nargs='?', default=expanduser('~/.abook/addressbook'),
                          help='The Abook file to process (default: ~/.abook/addressbook)')
      parser.add_argument('outfile', nargs='?', type=FileType('w'), default=stdout,
                          help='Output vCard file (default: stdout)')
      args = parser.parse_args()
  
      args.outfile.write(Abook(args.infile).to_vcf())