Showing the 2D coordinate systems

This application is more of a demonstration.

This chapter introduces:

• TODO

To make the text nicely formatted, there are many [something]_to_str helper functions, such as:

fn test_coordinate_to_str() {
    assert_eq!(
        coordinate_to_str(Vec2::new(1.2, 3.4)),
        String::from("(1.2, 3.4)")
    )
}

and:

fn test_ucoordinate_to_str() {
    assert_eq!(ucoordinate_to_str(UVec2::new(1, 2)), String::from("(1, 2)"))
}