project: Fix up documentation for Path Trie and add a test for having multiple present nodes (#34560)

cc @cole-miller I was worried with
https://github.com/zed-industries/zed/pull/34460#discussion_r2210814806
that PathTrie would not be able to support nested .git repositories, but
it seems fine.

Release Notes:

- N/A
dc8d0868ecPiotr Osiewicz committed on 7/16/2025, 5:24:34 PM· committed by GitHubparent58807f0
1 file changedLine totals unavailable