Preparing for depreciation of WheelchairVehicle

Adding a comment for future deletion since the object is marked as deprecated from v2.0

Author: TuThoThai

xsd/NeTEx_publication.xsd

@@ -13017,6 +13017,7 @@
 		</xsd:key>
 		<!-- =====WheelchairVehicle ================================ -->
 		<!-- =====WheelchairVehicle unique========================== -->
+		<!--This section can be deleted at the next update as WheelchairVehicle is marked deprecated since v2.0-->
 		<xsd:unique name="WheelchairVehicle_UniqueBy_Id_Version">
 			<xsd:annotation>
 				<xsd:documentation>Every [WheelchairVehicle Id + Version] must be unique within document.</xsd:documentation>