[crzwdjk]

> Also, if you have a bunch of `mod.rs` files open in your editor, you have no idea what module they corresponds to, as they all say `mod.rs`. Now they'll say the file name instead.

This is probably the most important reason to make the change tbh. It doesn't seem like a big thing but it's one of those ergonomic papercuts that will make the user experience subtly better once it's fixed.