Update release notes

Signed-off-by: Daniel Zullo <[email protected]>

Author: daniel-zullo-frequenz

RELEASE_NOTES.md

@@ -31,12 +31,11 @@
   - Add `fill_value` option to window method to impute missing values. By default missing values are imputed with `NaN`.
 - Add `at` method to `MovingWindow` to access a single element and use it in `__getitem__` magic to fully support single element access.
 
-
-
 - The PowerDistributingActor now supports n:m relations between inverters and
   batteries.
   This means that one or more inverters can be connected to one or more batteries.
 
+- The `ConnectionManager` fetches microgrid metadata when connecting to the microgrid and exposes `microgrid_id` and `location` properties of the connected microgrid.
 
 ## Bug Fixes