f comment and newline

Author: TheBlueMatt

lightning/src/ln/features.rs

@@ -610,6 +610,7 @@ impl<T: sealed::Context> Features<T> {
 		}
 		Ok(())
 	}
+
 	fn from_be_bytes(mut flags: Vec<u8>) -> Features<T> {
 		flags.reverse(); // Swap to little-endian
 		Self {
@@ -777,6 +778,9 @@ impl_feature_len_prefixed_write!(ChannelFeatures);
 impl_feature_len_prefixed_write!(NodeFeatures);
 impl_feature_len_prefixed_write!(InvoiceFeatures);
 
+// Because ChannelTypeFeatures only appears inside of TLVs, it doesn't have a length prefix when
+// serialized. Thus, we can't use `impl_feature_len_prefixed_write`, above, and have to write our
+// own serialization.
 impl Writeable for ChannelTypeFeatures {
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 		self.write_be(w)