[WB-1112] Clarify aria-label docs

Author: marcysutton

packages/wonder-blocks-date-picker/src/components/date-picker.tsx

@@ -62,7 +62,8 @@ interface Props {
      */
     footer?: (arg1: {close: () => unknown}) => React.ReactNode;
     /**
-     * The aria-label to be used for the date picker.
+     * The aria-label to be used for the date picker. This is only needed if there
+     * is no visible label associated with the date picker, such as with LabeledField.
      */
     inputAriaLabel?: string;
 }