Update release notes before release (#33)

Author: flora-hofmann-frequenz

RELEASE_NOTES.md

@@ -1,17 +1,5 @@
 # Frequenz Client Common Library Release Notes
 
-## Summary
-
-<!-- Here goes a general summary of what this release is about -->
-
 ## Upgrading
 
 * Upgrading metric `__init__` to names from api-common release [v0.6.0](https://github.com/frequenz-floss/frequenz-api-common/releases/tag/v0.6.0)
-
-## New Features
-
-<!-- Here goes the main new features and examples or instructions on how to use them -->
-
-## Bug Fixes
-
-<!-- Here goes notable bug fixes that are worth a special mention or explanation -->