Split.md seems wrong

It is my understanding that mod statements in crate roots (main.rs, lib.rs, etc.) refer to root files in src/ but that those files' mod statements refer to root files in sub-directories of the same name as them. Essentially, crate roots share src/ for their modules but each sub module must have their own child folder to contain their own sub modules. Consequently...

main.rs
lib.rs

src/
  args.rs
  drill/
     mod.rs
     handle.rs
     battery.rs
  tool2.rs
  hacksaw/
     handle.rs
     blade.rs
        blade/
           sawtooth.rs
           pairing.rs

Start by reading Split.md and compare its module-layout explanation with the Rust module structure described in this issue. Identify the part that conflicts with the reported understanding, then update the explanation and example so the intended layout is unambiguous; confirm that the resulting documentation addresses the issue's concern.