Document NodeMeasure type

crates/bevy_ui/src/measurement.rs

@@ -29,6 +29,10 @@ pub trait Measure: Send + Sync + 'static {
     ) -> Vec2;
 }
 
+/// A type to serve as Taffy's node context (which allows the content size of leaf nodes to be computed)
+///
+/// It has specific variants for common built-in types to avoid making them opaque and needing to box them
+/// by wrapping them in a closure and a Custom variant that allows arbitrary measurement closures if required.
 pub enum NodeMeasure {
     Fixed(FixedMeasure),
     #[cfg(feature = "bevy_text")]