docs/release-notes: add section re merge commit exemption

docs/release-notes/release-notes-0.14.0.md

@@ -4,7 +4,8 @@
 
 [A new pre-submit check has been
 added](https://github.com/lightningnetwork/lnd/pull/5520) to ensure that all
-PRs add an entry in the release notes folder that at leasts links to PR being
-added.
+PRs ([aside from merge
+commits](https://github.com/lightningnetwork/lnd/pull/5543)) add an entry in
+the release notes folder that at leasts links to PR being added.
 
 # Contributors (Alphabetical Order)