Add required dependencies, formatting

Cargo.toml

@@ -37,21 +37,27 @@ all-languages = [
     "japanese",
     "korean",
     "portuguese",
-    "spanish"
+    "spanish",
 ]
 
 [dependencies]
 rand_core = { version = ">=0.4.0, <0.7.0", optional = true }
 crate_rand = { package = "rand", version = ">=0.6.0, <0.9.0", optional = true }
-serde = { version = "1.0", default-features = false, features = [ "alloc" ], optional = true }
+serde = { version = "1.0", default-features = false, features = [
+    "alloc",
+], optional = true }
 
 # Enabling this feature raises the MSRV to 1.51
 zeroize = { version = "1.5", features = ["zeroize_derive"], optional = true }
 
-# Unexported dependnecies
+# Unexported dependencies
 bitcoin_hashes = { version = ">=0.12, <=0.13", default-features = false }
 unicode-normalization = { version = "0.1.22", default-features = false, optional = true }
 
+# faster PBKDF2 implementation
+fastpbkdf2 = { git = "https://github.com/invd/rust-fastpbkdf2.git", branch = "master" }
+itertools = { version = "0.8" }
+
 [dev-dependencies]
 # Enabling the "rand" feature by default to run the benches
 bip39 = { path = ".", features = ["rand"] }