Clarify supported features flags set

Author: TheBlueMatt

lightning/src/ln/features.rs

@@ -81,7 +81,13 @@ impl InitFeatures {
 	/// Create a Features with the features we support
 	pub fn supported() -> InitFeatures {
 		InitFeatures {
-			flags: vec![2 | 1 << 5, 1 << (9-8) | 1 << (15 - 8), 1 << (17 - 8*2)],
+			flags: vec![
+				1 << 1 |          // data_loss_protect supported
+				1 << 5,           // upfront_shutdown_script supported
+				1 << (9  - 8*1) | // variable_length_onion supported
+				1 << (15 - 8*1),  // basic_mpp supportedyment_secret supported
+				1 << (17 - 8*2)   // basic_mpp supported
+			],
 			mark: PhantomData,
 		}
 	}