fix doc comments

Author: Evanfeenstra

lightning/src/onion_message/packet.rs

@@ -37,9 +37,9 @@ pub(super) const BIG_PACKET_HOP_DATA_LEN: usize = 32768;
 pub struct Packet {
 	/// Bolt 04 version number
 	pub version: u8,
-	/// The PublicKey used during shared secret generation
+	/// A random sepc256k1 point, used to build the ECDH shared secret to decrypt hop_data
 	pub public_key: PublicKey,
-	/// 1300 bytes payload for the next hop
+	/// Encrypted payload for the next hop
 	//
 	// Unlike the onion packets used for payments, onion message packets can have payloads greater
 	// than 1300 bytes.