iAmOnCourseHomepage step should be backported (and documented)

To avoid forgetting it, the iAmOnCourseHomepage step (I am on "XXX" course homepage) should be backported and documented, so people can move to it and keep the same features working over a number of (plugin and core) branches. it's useful for both.

Also it should be documented and shown as a replacement for the old one.

Note: there is also the "with editing mode on" alternative to backport and document.

Ciao