Add ability to add parallax for individual sections

sectionParallax.js

function onScroll(e) {
    console.log(e);

    console.log('yes');
}

var observer = new IntersectionObserver(entries => {
    console.log(entries)
    entries.forEach(entry => {
        console.log(entry)
    if (entry.isIntersecting === true && entry.intersectionRatio > 0) {
        entry.target.style.transform = translateY(entry.intersectionRatio, '20%')
    } else {
        document.removeEventListener('scroll', onScroll, {capture:false,passive:true});
    }
    });
}, {threshold: buildThresholdList()});


var sections = document.querySelectorAll('section');
sections.forEach(item => {
    observer.observe(item)
});

function buildThresholdList() {
  let thresholds = [];
  let numSteps = 100;

  for (let i=1.0; i<=numSteps; i++) {
    let ratio = i/numSteps;
    thresholds.push(ratio);
  }

  thresholds.push(0);
  return thresholds;
}

function translateY(ratio, total) {
    return `translateY(calc(-${ratio} * ${total})`;
  }