Learning Rust concepts: let, mut, match, arms, cargo, references, and shadowing.
The let keyword is used to declare new variables into the current scope. The mut (mutable) keyword specifies the variable's value can change.
The match keyword provides pattern-matching expressions made up of arms. An arm is a pattern to match against.
Cargo is the package manager for Rust.
A reference is a way to let multiple parts of our code access one piece of data without copying that data into memory multiple times.
Shadowing lets us reuse variable names, preventing the creation of two or more unique variables. Shadowing is often used to convert a value from one type to another.