Clean up release notes to prepare for release v0.6.1

Signed-off-by: Tiyash Basu <[email protected]>

Author: tiyash-basu-frequenz

RELEASE_NOTES.md

@@ -2,17 +2,9 @@
 
 ## 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 -->
+This release adds a new component category `COMPONENT_CATEGORY_HVAC` to the API.
 
 ## New Features
 
 - A new component category `COMPONENT_CATEGORY_HVAC` has been added to the API
   to represent HVAC (Heating, Ventilation, and Air Conditioning) systems.
-
-## Bug Fixes
-
-<!-- Here goes notable bug fixes that are worth a special mention or explanation -->