and tweak command/screen headings.
This goes further in the direction of showing simple lists of topics
instead of outlines. mdbook-toc doesn't support configuring the TOC
depth this per page, so it has to be site wide.
Overall I feel this is better, see eg the hledger manual. It hides a
lot of interesting topic names but a shorter, linear list is less
scary and clearer than a huge scrolling outline. Once you click in to
a section and find a subsection of interest, it's still easy to
bookmark/share those by clicking their heading.