Clear release notes

Signed-off-by: cwasicki <[email protected]>

Author: cwasicki

RELEASE_NOTES.md

@@ -6,13 +6,8 @@
 
 ## Upgrading
 
-* Upgrading "frequenz-api-reporting >= 0.1.1, < 0.2" to "frequenz-api-reporting >= 0.2.0, < 0.3"
-* Upgrading "frequenz-client-common == 0.1.0" to "frequenz-client-common >= 0.2.0, < 0.3"
-
 ## New Features
 
-* An API key for authorization can now be passed to the `ReportingApiClient`.
-
 ## Bug Fixes
 
 <!-- Here goes notable bug fixes that are worth a special mention or explanation -->