Display stage/group ownership info

From discussing with @jsandlin earlier today, it would have helped him if the stage and group data for a page were visible somewhere on the page to communicate ownership of a page.

Could we craft something to extract the metadata and display it somewhere on the page (sidebar? bottom? somewhere?) and cross-link to the relevant section of https://about.gitlab.com/handbook/product/categories/#devops-stages so users know who to contact?