You can force the browser to ignore the cert error manually, but id doesn't work loading as a resource. Try the following
```html
<!DOCTYPE html>
<html lang="en">
<head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <meta charset="utf-8">
  <title>HTTPS Test</title>
  <script src="https://squizlabs.github.io/HTML_CodeSniffer/build/HTMLCS.js"></script>
</head>
<body>
Test HTTPS
</body>
</html>
```