@cfware/loading 
Display a loading spinner until the loaded attribute is set to the document body.
Usage
Create loading.js:
import '@cfware/loading';Create index.html:
<!doctype html>
<html lang="en-US">
<head>
<meta charset="utf-8">
<script type="module" src="loading.js"></script>
<script type="module" defer src="app.js"></script>
</head>
<body>
</body>
</html>Create app.js, ensure it runs document.body.setAttribute('loaded', '') when the
application is ready to be displayed.