Hilbert transforms between 1D and 2D space, optimized for u16 coordinates.
```rust use hilbert16::{Curve, Point};
let order = 9; let curve = Curve::new(order).unwrap();
let p = Point { x: 175, y: 295 }; println!("{:?} => {}", p, curve.distat(p).unwrap(); let d = 94085; println!("{} => {:?}", d, curve.point_at(d).unwrap(); ```