Navigate within large markdown block

[kjk]

We have Ctrl + B to navigate between blocks.

Add a command (Navigate within Markdown ?) that allows navigating within a large markdown block.

We would construct table of contents based on headers H1 - H4 (i.e. # to ####) with similar UI to Ctrl + B and Ctrl + P.

We would indent h2 - h4, so it displays like a tree.