Update release notes

Signed-off-by: Simon Völcker <simon.voelcker@frequenz.com>

Author: simonvoelcker

RELEASE_NOTES.md

@@ -14,6 +14,10 @@
 
 - The resampler's `max_age_in_intervals` has also become configurable, through `LogicalMeterConfig`.
 
+- New method `MockMicrogridApiClient::augment_electrical_component_bounds` captures requests so that these can be used in test cases. Obtain the list of captured requests using `MockMicrogridApiClient::augment_bounds_calls_handle` (also new).
+
+- New method `MockComponent.add_component_bounds` allows to add metric bounds to a mock component.
+
 ## Bug Fixes
 
 <!-- Here goes notable bug fixes that are worth a special mention or explanation -->