Added release notes

doc/releasenotes.md

@@ -9,6 +9,11 @@
     - These filters are specified in the ***eventFilters*** of the subscription if the ***Enhanced Event Report*** feature of the ***Supported Features*** is activated.
 - More detailed information about event filters can be found in [Event Filter].
 
+### **Testing**
+
+- New Event Filter test suite with 8 tests. [Event Filter](./testing/testplan/event_filter/README.md)
+
+
 ### **Technical Debt Solved**
 
 #### **Hardening on startup scripts for services interacting with Vault**