JS: change notes for persistent storage taint step and cookie models

Author: Esben Sparre Andreasen

change-notes/1.20/analysis-javascript.md

@@ -4,8 +4,11 @@
 
 * Support for popular libraries has been improved. Consequently, queries may produce more results on code bases that use the following features:
   - client-side code, for example [React](https://reactjs.org/)
+  - cookies and webstorage, for example [js-cookie](https://github.com/js-cookie/js-cookie)
   - server-side code, for example [hapi](https://hapijs.com/)
 
+* The taint tracking library now recognizes flow through persistent storage, this may give more results for the security queries. 
+
 ## New queries
 
 | **Query**                                     | **Tags**                                             | **Purpose**                                                                                                                                                                 |