Construct a reference node for a JIRA ticket.

def _make_ticket_node(ticket_id, config, options=None):
    """Construct a reference node for a JIRA ticket."""
    options = options or {}
    ref = config.jira_uri_template.format(ticket=ticket_id)
    link = nodes.reference(text=ticket_id, refuri=ref, **options)
    return link