Feature request: visual marker for scrolling

[mark2185]

How would one add a marker to the bottom or top of the view before scrolling with d or u?

For example - if I'm reading a wall of text and press d, sometimes I don't notice where is the continuation of what I was reading, but if there was a yellow horizontal line that moves with the page content, I know where I should look after scrolling.

It's a minor thing, but I'm just curious how would one add something like that.