fixup! add the bolt12 invoice to the PaymentSend event

Signed-off-by: Vincenzo Palazzo <[email protected]>

Author: vincenzopalazzo

lightning/src/events/mod.rs

@@ -940,6 +940,11 @@ pub enum Event {
 		/// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
 		fee_paid_msat: Option<u64>,
 		/// The bolt12 invoice that was paid. `None` if the payment was a non-bolt12 payment.
+		///
+		/// The bolt12 invoice is useful for proof of payment because it contains the
+		/// payment hash. A third party can verify that the payment was made by
+		/// showing the invoice and confirming that the payment hash matches
+		/// the hash of the payment preimage.
 		bolt12_invoice: Option<Bolt12Invoice>,
 	},
 	/// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events