Adding ml-kem re-export (#414)

Author: kevinlewi

src/lib.rs

@@ -1383,6 +1383,8 @@ mod tests;
 
 #[cfg(feature = "argon2")]
 pub use argon2;
+#[cfg(feature = "kem")]
+pub use ml_kem;
 pub use {generic_array, rand};
 
 pub use crate::ciphersuite::CipherSuite;