docs: add release-notes.

docs/release-notes/release-notes-0.18.0.md

@@ -130,6 +130,10 @@
 * [Fixed](https://github.com/lightningnetwork/lnd/pull/8685) lncli "bumpfee"
   parsing of the immediate/force flag.
   
+* [Fixed](https://github.com/lightningnetwork/lnd/pull/8621) the behaviour of
+  neutrino LND nodes which would loose sync in case they had very unstable
+  peer connection.
+
 # New Features
 ## Functional Enhancements