Update format_release_notes.rst

Author: mavaylon1

docs/format/source/format_release_notes.rst

@@ -12,6 +12,7 @@ Minor changes
 - Deprecated `ImagingRetinotopy` neurodata type. (#565)
 - Modified `OptogeneticSeries` to allow 2D data, primarily in extensions of `OptogeneticSeries`. (#564)
 - Added optional ``stimulus_template`` column to ``IntracellularStimuliTable`` as part of the ``IntracellularRecordingsTable``. (#545)
+- Added optional `bounds` attribute to `SpatialSeries.data`. (#567)
 
 2.6.0 (January 17, 2023)
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