doc: add notable-change mention to sec release

PR-URL: #55830
Refs: nodejs/changelog-maker#167
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/contributing/releases.md

@@ -311,6 +311,9 @@ $ git checkout -b v1.2.3-proposal upstream/v1.x
 git cherry-pick  ...  # cherry-pick nodejs-private PR commits directly into the proposal
 ```
 
+Be sure to label the CVE fixes as `notable-change` in the nodejs-private repository.
+This will ensure they are included in the "Notable Changes" section of the CHANGELOG.
+
 </details>
 
 ### 3. Update `src/node_version.h`