Detect WebP
<script src="<module-dir>/lib/WebModule.js"></script>
<script src="<module-dir>/lib/WebPDetector.js"></script>
<script>
WebPDetector.LOSSY // -> true / false
WebPDetector.LOSSLESS // -> true / false
WebPDetector.ALPHA // -> true / false
WebPDetector.ANIMATION // -> true / false
</script>