Prepare release notes for v0.7.0

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

RELEASE_NOTES.md

@@ -1,9 +1,5 @@
 # Frequenz Microgrid API Client Release Notes
 
-## Summary
-
-<!-- Here goes a general summary of what this release is about -->
-
 ## Upgrading
 
 - Now component and microgrid IDs are wrapped in new classes: `ComponentId` and `MicrogridId` respectively.
@@ -16,11 +12,3 @@
    - Ensuring proper hash behavior in collections.
 
    To migrate you just need to wrap your `int` IDs with the appropriate class: `0` -> `ComponentId(0)` / `MicrogridId(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 -->