fix ie and edge mousewheel jitter

sitelayout_scripts.js

if (navigator.userAgent.match(/Trident\//) || navigator.userAgent.match(/Edge\//)) {
    document.body.addEventListener("mousewheel", function(evt) {
        evt.preventDefault();
        var wd = evt.wheelDelta;
        var csp = window.pageYOffset;
        window.scrollTo(0, csp - wd);
    });
}