Add module documentation to geometry and labeling mods

Author: elevans

cellcast/src/geometry/mod.rs

@@ -1 +1,2 @@
+//! Geometry structs and functions for 2D and 3D data.
 pub mod polygon;

cellcast/src/labeling/mod.rs

@@ -1,2 +1,3 @@
+//! Labeling functions for 2D and 3D data.
 pub mod polygon_label;
 pub use polygon_label::radial_polygon_to_label_2d;

cellcast/src/labeling/polygon_label.rs

@@ -1,3 +1,7 @@
+//! Polygon to label conversion functions.
+//!
+//! This module provides functions for converting radial polygon representation
+//! into 2D and 3D label images.
 use std::f32::consts::TAU;
 
 use ndarray::{Array2, Array3, ArrayView1, ArrayView2, Axis};