[x] Clicking on a message title should scroll the table of contents to that message. I think this makes sense in a symmetric fashion to clicking on TOC.
[x] Avoid triggering when clicking link
[x] Avoid triggering when selecting text?
[x] Scroll smoothly unless prefers-reduced-motion
[ ] Ideally open up folded TOC parents to reveal child (like scrollToMessage) -- this would require a significant change to how TOC folding works
[x] Trigger an animation on the specific TOC item, for when couldn't scroll to match up with message (near extremes)
[x] *Hovering on a message title should highlight the corresponding TOC item, or if off-screen, a border at the top or bottom. (Replacing current red underline which is weird.)
[ ] Message title should also be draggable into table of contents.
scrollToMessage) -- this would require a significant change to how TOC folding worksRelated: #552