Fix: aria-valuetext attribute added to the slider to read out prefix/…

…suffix (fixes #211)

templates/slider.jsx

@@ -177,6 +177,7 @@ export default function Slider (props) {
           <input className='slider__item-input js-slider-item-input'
             type='range'
             aria-label={ariaScaleName}
+            aria-valuetext={`${scaleStepPrefix} ${selectedValue} ${scaleStepSuffix}`}
             value={selectedValue}
             min={_scaleStart}
             max={_scaleEnd}