serve images in nextgen formats webp

1<picture>
2  <source srcset="img/awesomeWebPImage.webp" type="image/webp">
3  <source srcset="img/creakyOldJPEG.jpg" type="image/jpeg"> 
4  <img src="img/creakyOldJPEG.jpg" alt="Alt Text!">
5</picture>

1.no-webp .elementWithBackgroundImage {
2  background-image: url("image.jpg");
3}
4
5.webp .elementWithBackgroundImage{
6  background-image: url("image.webp");
7}