chore: update release notes

Signed-off-by: Matthias Wende <[email protected]>

Author: matthias-wende-frequenz

RELEASE_NOTES.md

@@ -1,17 +1,10 @@
 # Frequenz Electricity Trading API Client 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
 
 - Update to API v0.7.0
 
 ## Bug Fixes
 
 - Ensure timestamp conversion errors are surfaced
+- Use HasField to check explicit field precedence