[Feature] Scroll sidebar when scrolling page

[seshrs]

When a user scrolls to a section whose sidebar item is not in view, the sidebar should scroll to make the item visible.

I think the sidebar should scroll so the active section is in the middle of the sidebar view, so that if the user scrolls to the previous or next section, no additional sidebar scrolling is required.

Edit: After some further thought, I wonder if this should be a choice that students can opt-in/out of from the settings view. Suggestions and opinions are welcome 😃