split up core/storage from the rest of the crates in the docstring for the top-level crate
//! Data types, collections, and algorithms for working with maps on 2D and 3D integer lattices.
//! Commonly known as pixel or voxel data.
//!
-//! This library is organized into several crates:
+//! This library is organized into several crates. The most fundamental are:
//! - **core**: lattice point and extent data types
+//! - **storage**: storage for lattice maps, i.e. functions defined on `Z^2` and `Z^3`
+//!
+//! Then you get extra bits of functionality from the others:
//! - **image**: conversion of 2D lattice maps to/from images
//! - **mesh**: 3D isosurface generation algorithms, smooth and cubic
//! - **procgen**: procedural generation of lattice maps, including sampled SDFs and height maps
//! - **search**: search algorithms on lattice maps
-//! - **storage**: storage for lattice maps, i.e. functions defined on `Z^2` and `Z^3`
//! - **vox**: conversion of 3D lattice maps to/from VOX data format
//!
//! To learn the basics about lattice maps, start with these doc pages:
