Update release notes after release (frequenz-floss#188)

Author: flora-hofmann-frequenz

RELEASE_NOTES.md

@@ -6,9 +6,7 @@
 
 ## Upgrading
 
-* Change 'start_dt' and 'end_dt' to 'start_time' and 'end_time' respectively.
-* Rename 'list' to 'receive' in component data retrival functions
-* Return the receiver directly in '_recieve_microgrid_components_data_batch'
+<!-- Here goes notes on how to upgrade from previous versions, including deprecations and what they should be replaced with -->
 
 ## New Features