How to publish a Rust crate

[mre]

What?

Write a simple Rust crate and publish it on crates.io

Why?

The goal is to show how simple it is to create a new crate, explain some best-practices
and why it's a good thing to create a crate in the first place.

How?

The crate doesn't need to be particularly useful, as long as the publishing part and the ecosystem is well explained.