Update OnionMessage with link to BOLTs

Author: elnosh

lightning-types/src/features.rs

@@ -54,8 +54,7 @@
 //! - `SimpleClose` - requires/supports simplified closing negotiation
 //!   (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#closing-negotiation-closing_complete-and-closing_sig) for more information).
 //! - `OnionMessages` - requires/supports forwarding onion messages
-//!   (see [BOLT-7](https://github.com/lightning/bolts/pull/759/files) for more information).
-//     TODO: update link
+//!   (see [BOLT-4](https://github.com/lightning/bolts/blob/master/04-onion-routing.md#onion-messages) for more information).
 //! - `ChannelType` - node supports the channel_type field in open/accept
 //!   (see [BOLT-2](https://github.com/lightning/bolts/blob/master/02-peer-protocol.md) for more information).
 //! - `SCIDPrivacy` - supply channel aliases for routing

lightning/src/ln/msgs.rs

@@ -767,9 +767,9 @@ pub struct UpdateAddHTLC {
 	pub blinding_point: Option<PublicKey>,
 }
 
-/// An onion message to be sent to or received from a peer.
+/// An [`onion message`] to be sent to or received from a peer.
 ///
-// TODO: update with link to OM when they are merged into the BOLTs
+/// [`onion message`]: https://github.com/lightning/bolts/blob/master/04-onion-routing.md#onion-messages
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub struct OnionMessage {
 	/// Used in decrypting the onion packet's payload.