library: document root module

src/lib.rs

@@ -1,9 +1,14 @@
 #![warn(missing_docs)]
 
+//! A pathtracing crate
+
 use bvh::nalgebra::{Point2, Point3, Vector3};
 
+/// A 2D point coordinate
 pub type Point2D = Point2<f32>;
+/// A 3D point coordinate
 pub type Point = Point3<f32>;
+/// A 3D vector
 pub type Vector = Vector3<f32>;
 
 pub mod core;