f - expand OfferBuilder::path docs

Author: jkczyz

lightning/src/offers/offer.rs

@@ -149,7 +149,8 @@ impl OfferBuilder {
 
 	/// Sets a blinded path for the offer.
 	///
-	/// Successive calls to this method will add another blinded path.
+	/// Successive calls to this method will add another blinded path. Caller is responsible for not
+	/// adding duplicate paths.
 	pub fn path(mut self, path: BlindedPath) -> Self {
 		self.offer.paths.get_or_insert_with(Vec::new).push(path);
 		self