fix stale doc comment
//!
//! # Serialization
//!
-//! In order to efficiently serialize a `ChunkMap`, you can first use `SerializableChunks::from_chunk_map` to create a compact
+//! In order to efficiently serialize a `ChunkMap`, you can first use `SerializableChunks::from_iter` to create a compact
//! serializable representation. It will compress the bincode representation of the chunks.
//!
//! # Example `ChunkHashMap` Usage
