A cargo plugin for showing an overview of a crate's modules.

With time, as your Rust projects grow bigger and bigger, it gets more and more
important to properly structure your code.
Fortunately Rust provides us with a quite sophisticated module system, allowing
us to neatly split up our crates into arbitrarily small sub-modules of types
and functions.

While this helps to avoid monolithic and unstructured chunks of code, it can
also make it hard at times to still mentally stay on top of the over-all
high-level structure of the project at hand.

This is where cargo-modules comes into play.