improve OctreeSet docstring
//! One possible use case is to construct one using `OctreeSet::from_array3`, then insert it into an `OctreeDBVT` in order to
//! perform spatial queries like raycasting.
//!
-//! You might also use an `OctreeSet` as a chunk index, where each point represents a single chunk. This representation is
+//! The `OctreeSet` is also used in the `OctreeChunkIndex`, where each point represents a single chunk. This representation is
//! useful for level of detail algorithms like clipmap traversal because inner nodes may correspond to downsampled chunks stored
//! in a `ChunkPyramid`.
//!
