Auto merge of #75293 - poliorcetics:intra-doc-links-std-path, r=jyn514

Move to intra-doc links in library/std/src/path.rs

Helps with #75080.

@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc

Known issue: The following links are broken (they are inside trait impls, undocumented in this file, inheriting from the original doc):

- [`Hasher`]
- [`Self`] (referencing `../primitive.slice.html`)
- [`Ordering`]

Author: bors