docs: add release note for 7705

Author: ellemouton

docs/release-notes/release-notes-0.16.3.md

@@ -6,5 +6,12 @@ Optimized [mempool
 management](https://github.com/lightningnetwork/lnd/pull/7681) to lower the CPU
 usage.
 
+## Bug Fixes
+
+* [Re-encrypt/regenerate](https://github.com/lightningnetwork/lnd/pull/7705)
+  all macaroon DB root keys on `ChangePassword`/`GenerateNewRootKey`
+  respectively.
+
 # Contributors (Alphabetical Order)
+* Elle Mouton
 * Yong Yu