Add read-time estimates to resources

It could be useful if estimates of how long it takes to read/watch/listen to a resource were displayed.

(I'm not sure if there is some kind of AI tool that could do this: https://martech.org/estimated-reading-times-increase-engagement/)

This would support students time management and engagement, as well as prompt lecturers to (re)consider the reasonability/feasibility of how much work they are assigning for their students.