Macro assets 

macro_rules! assets {
    (timeout: $timeout:expr, $($asset:expr),*) => { ... };
    ($($asset:expr),*) => { ... };
}

Constructs an Assets object for use in a scene. Example:

{
    Image::new("ramen", "/pics/ramen.png"),
    Image::new("noise", "/pics/noise.bmp"),
    Audio::new("ambient_music", "/audio/Ephemeral/Coin Machine.mp3"),
    mixin!
    {
        "intersect_ray", 
        ("raycaster", component!
        {
            RayCaster,
            objects: List(Cow::Borrowed(&[Cow::Borrowed("#ramen-cube, #water")]))
        })
    }
},