def _link(subs, shared):
    """Configure the `doorstop link` subparser."""
    info = 'add a new link between two items'
    sub = subs.add_parser('link', description=info.capitalize() + '.', help
        =info, **shared)
    sub.add_argument('child', help='child item UID to link to the parent')
    sub.add_argument('parent', help='parent item UID to link from the child')
