f doc what pubkey is

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -513,7 +513,10 @@ enum BackgroundEvent {
 	///
 	/// Note that any such events are lost on shutdown, so in general they must be updates which
 	/// are regenerated on startup.
-	MonitorUpdateRegeneratedOnStartup((PublicKey, OutPoint, ChannelMonitorUpdate)),
+	MonitorUpdateRegeneratedOnStartup((
+		/// The counterparty node_id for the channel being updated.
+		PublicKey,
+		OutPoint, ChannelMonitorUpdate)),
 }
 
 #[derive(Debug)]