message: fix backtik typo
diff: @@ -262,7 +262,7 @@ async function _embed(
  const div = typeof el === 'string' ? document.querySelector(el) : el;
  if (!div) {
  - throw Error('${el} does not exist');
  + throw Error(`${el} does not exist`);
  }
  div.classList.add('vega-embed');
  