can you please document this property as well? its the external link in case this page is to be considered an external link menu item, right?

hm, makes me wonder if we really should support that option here. it makes the rest of the properties of the page quite pointless, especially if the document happens to be used in routing. would it then redirect? maybe we should do a RedirectPage instead that is at the same time RedirectRoute and a MenuNode that provides the linked url.