Update format_release_notes.rst

Author: rly

docs/format/source/format_release_notes.rst

@@ -6,13 +6,17 @@ Release Notes
 2.8.0 (Upcoming)
 ------------------------
 
-Minor changes
+Major changes
 ^^^^^^^^^^^^^
-- Added optional ``was_generated_by`` attribute to ``NWBFile`` to store provenance information (#578)
 - Deprecated ``EventWaveform`` neurodata type. (#584)
 - Deprecated ``ImageMaskSeries`` neurodata type. (#583)
+- Changed ``NWBFile.electrodes`` from a generic ``DynamicTable`` with added columns to an ``ElectrodesTable`` that extends ``DynamicTable`` with added columns. (#539)
+
+Minor changes
+^^^^^^^^^^^^^
+- Added optional ``was_generated_by`` attribute to ``NWBFile`` to store provenance information. (#578)
 - Made ``band_mean`` and ``band_std`` in ``DecompositionSeries`` optional. (#593)
-- Added ``Device.model_number``, ``Device.model_name``, ``Device.serial_number`` (#594)
+- Added ``Device.model_number``, ``Device.model_name``, ``Device.serial_number``. (#594)
 
 2.7.0 (February 7, 2024)
 ------------------------