It would be great if a custom layout for the side navigation could auto-populate when pages are added.
This is similar to sphinxdoc / readthedoc's toctree macro, especially with "globbing"
I see this as an enhancement to the tree-based navigation, especially with the drop-down menu suggestion
with a folder structure of
index (with toc)
|--file1 (with toc)
root index has
testdir index has
and it produces the attached layout.
new files placed in the subdirectories would automatically appear at the correct nesting level in the navigation
some good examples (not mine, just popular pages):