speck: fix documentation field (#521)

Author: sorairolake

speck/Cargo.toml

@@ -4,7 +4,7 @@ version = "0.1.0-rc.2"
 authors = ["RustCrypto Developers"]
 license = "Apache-2.0 OR MIT"
 description = "Speck block cipher algorithm"
-documentation = "https://docs.rs/speck"
+documentation = "https://docs.rs/speck-cipher"
 repository = "https://github.com/RustCrypto/block-ciphers/tree/master/speck"
 readme = "README.md"
 edition = "2024"