Fix back button behavior

[techieshark]

I've noticed people click the back button instead of scrolling up. That's perhaps understandable since they're clicking a button instead of scrolling down.

We could use the History API to keep track of their history inside the page and make it so when they click the back button it scrolls up (or whatever is appropriate in that case).

Needs testing / research to figure out how necessary this is and flesh out how the interaction should work.