My version gulp-webp-html. Fixed bug with the disappearance of line breaks after the execution of the plugin.
// Input
<img src="/images/catalogImage.jpg">
// Output
<picture>
<source srcset="/images/catalogImage.webp" type="image/webp">
<img src="/images/catalogImage.jpg">
</picture>
npm i -D git://github.com/TigroWeb/gulp-webp-html2.git
var GulpWebpHtml2 = require('gulp-webp-html2');
gulp.task('html',function(){
gulp.src('./assets/**/*.html')
.pipe(GulpWebpHtml2())
.pipe(gulp.dest('./public/'))
});