Clear release notes (#1301)

Author: shsms

RELEASE_NOTES.md

@@ -1,5 +1,17 @@
 # Frequenz Python SDK Release Notes
 
+## Summary
+
+<!-- Here goes a general summary of what this release is about -->
+
+## Upgrading
+
+<!-- Here goes notes on how to upgrade from previous versions, including deprecations and what they should be replaced with -->
+
+## New Features
+
+<!-- Here goes the main new features and examples or instructions on how to use them -->
+
 ## Bug Fixes
 
-- Doesn't repeat zero commands to battery inverters anymore, to not interfere with lower level logic that might want to do things only when there are no actors trying to use the batteries.
+<!-- Here goes notable bug fixes that are worth a special mention or explanation -->