Use the new module naming convension instead of old-skool mod.rs files

[BenLeadbetter]

We use the old-skool rust submodule naming convension of using mod.rs files. Recommended best practice is to use the new alternative naming scheme.

Note: Prior to rustc 1.30, using mod.rs files was the way to load a module with nested children. It is encouraged to use the new naming convention as it is more consistent, and avoids having many files named mod.rs within a project.

More info:

• Docs: https://doc.rust-lang.org/reference/items/modules.html
• Original query on reddit: https://www.reddit.com/r/rust/comments/1coi7vu/comment/l3f4s2f/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button