update release note

Author: brucewzj99

release_notes.md

@@ -59,4 +59,10 @@
 - Rename retrievetransaction to getdaytransaction
 
 ### For Developer 🧑‍💻
-- When you run test.py, ngrok will auto setup with the correct webhook!
+- When you run test.py, ngrok will auto setup with the correct webhook!
+
+
+## Version 2.1.1 - Date 8 Jun 2023
+### Enhancement 🔥
+- Migrate to use firestore
+- Reformatted get overall transaction