f update comment

Author: TheBlueMatt

lightning/src/ln/features.rs

@@ -71,11 +71,11 @@ mod sealed {
 	use prelude::*;
 	use ln::features::Features;
 
-	/// The context in which [`Features`] are applicable. Defines which features are required and
-	/// which are optional for the context.
+	/// The context in which [`Features`] are applicable. Defines which features are known to the
+	/// implementation, though specification of them as required or optional is up to the code
+	/// constructing a features object.
 	pub trait Context {
-		/// Bitmask for selecting features that are known to the implementation, regardless of
-		/// whether each feature is required or optional.
+		/// Bitmask for selecting features that are known to the implementation.
 		const KNOWN_FEATURE_MASK: &'static [u8];
 	}
 
@@ -89,8 +89,6 @@ mod sealed {
 
 			impl Context for $context {
 				const KNOWN_FEATURE_MASK: &'static [u8] = &[
-					// Similar as above, but set both flags for each feature regardless of whether
-					// the feature is required or optional.
 					$(
 						0b00_00_00_00 $(|
 							<Self as $known_feature>::REQUIRED_MASK |