update doc

crates/katana/core/src/service/messaging/mod.rs

@@ -12,8 +12,8 @@
 //! The sending of the messages is realized by collecting all the `messages_sent` from local
 //! execution of smart contracts using the `send_message_to_l1_syscall`. Once messages are
 //! collected, the hash of each message is computed and then registered on the settlement layer to
-//! be consumed on the latter (by manually by sending a transaction on the settlement chain).
-//! The hashes are registered using a custom contract that mimics the verification of Starknet block
+//! be consumed on the latter (by manually sending a transaction on the settlement chain). The
+//! hashes are registered using a custom contract that mimics the verification of Starknet block
 //! on Ethereum, since this process of proving and verifying a block is not present with local dev
 //! nodes.
 //!