This commit applies 'cargo fix --edition' to safely migrate the project
to Edition 2021 of Rust.
A rustfmt.toml has also be added to enforce the flattening of use
statements when running 'cargo fmt'.
Woke up today and thought this would be a cool way to learn more about
deriving functionality with proc macros.
Hopefully having this wrapper/helper library will make first time
configuration for new users easier.
