docs: OO.ui.CapsuleMultiSelectWidget: Link to the widget it uses
docs: OO.ui.CapsuleMultiSelectWidget: Link to the widget it uses

Change-Id: Ia486af2ebc24bb12ed88bcd701c9b1ae52602fb7

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui