Expandable ToC might be nice

[rmustacc]

One thing that comes tom ind for me is that sometimes I want to get into a really nested part of a doc via its ToC. I think the default choice we have around how much is rendered is pretty reasonable. I wonder if there's some way we could have an optional way to expand and reduce a given range of ToC ala what you get with say Firefox's pdf viewer. I dunno that this is worth the effort though.

[benjaminleonard]

Good suggestion – at the very least I think we might be able to unbound the ToC range on smaller screens since it's full-width and there's a little more room to work with.