<div id="container">
We 💓 TypeScript!
</div>
 
<script src="lib/text-highlighter.js"></script>
<script>
  var textHighlighter = new TextHighlighter(document.getElementById('container'));
  // apply highlight
  textHighlighter.highlight('typescript');
 
  // remove highlight
  textHighlighter.dehighlight();
</script> 

before
 
<div id="container">
We 💓 ＴｙｐｅＳｃｒｉｐｔ!
</div>
 
<script>
  ...
  // apply highlight
  textHighlighter.highlight('typescript');
</script> 
 
after
 
<div id="container">
We 💓 <mark>ＴｙｐｅＳｃｒｉｐｔ</mark>!
</div>