An option to make a page invisible in the wikipakk menu

As a sort of replacement for the excerpt macro in Confluence, we wanted to embed content of a page into multiple other pages. The text that needs to be shown on multiple pages would be put in a completely separate page, but that page is then also displayed in the menu, while it is only a page that is to be included in other pages, so it would be nicer if it could be made hidden from the menu.
