doc: release-notes-0.22.0

Author: MPins

docs/release-notes/release-notes-0.22.0.md

@@ -83,9 +83,16 @@
 
 ## Code Health
 
+* [Removed](https://github.com/lightningnetwork/lnd/pull/10891) the staging
+  feature bits for the RBF-based co-op close protocol
+  (`rbf-coop-close-x`, bits 160/161). Now that the final feature bits
+  (`rbf-coop-close`, bits 60/61) have been in production for a while, the
+  staging bits are no longer signaled or negotiated.
+
 ## Tooling and Documentation
 
 # Contributors (Alphabetical Order)
 
 * Boris Nagaev
 * Erick Cestari
+* Pins