f Expand docs a bit

Author: tnull

lightning/src/ln/channelmanager.rs

@@ -6324,7 +6324,10 @@ where
 
 	/// Processes HTLCs which are pending waiting on random forward delay.
 	///
-	/// Will regularly be called by the background processor.
+	/// Will be regularly called by LDK's background processor.
+	///
+	/// Users implementing their own background processing logic should call this in irregular,
+	/// randomly-distributed intervals.
 	pub fn process_pending_htlc_forwards(&self) {
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(self);