fix docs about snap
//! written back to the `ChunkMap` using the `flush_chunk_cache` method.
//!
//! Two compression backends are usable. The default is LZ4, which has the best tradeoff of
-//! compression rate and speed. The other is Lz4, which has a pure-rust implementation. Lz4
-//! can be used by enabling the "Lz4" feature.
+//! compression rate and speed. The other is snap, which has a pure-rust implementation. Snap
+//! can be used by enabling the "snappy" feature.
//!
//! # Example Usage
//! ```
