get truthy value from key from `URLSearchParams`

get-truthy-querystring.js

const qs = new URLSearchParams(window.location.search);
function getTruthyQS (key) {
  if (!qs || !qs.has(key)) {
    return false;
  }
  const valueLower = (qs.get('key') || '').trim().toLowerCase();
  return valueLower === '' || valueLower === '1' || valueLower === 'true' || valueLower === 'yes' || valueLower === 'on';
}