docs: add release not for pathfinding

Author: Abdulkbk

docs/release-notes/release-notes-0.21.0.md

@@ -79,6 +79,10 @@
   for peer-to-peer communication.
 
 ## Functional Enhancements
+* Added [pathfinding support](https://github.com/lightningnetwork/lnd/pull/10612)
+  for routing onion messages. The router can now find paths through the channel 
+  graph specifically filtered for nodes that advertise support for onion
+  messaging (feature bit 38/39).
 
 * [Added reorg protection for channel
   closes](https://github.com/lightningnetwork/lnd/pull/10331). Previously,
@@ -346,6 +350,7 @@
 
 # Contributors (Alphabetical Order)
 
+* Abdulkbk
 * bitromortac
 * Boris Nagaev
 * Elle Mouton