title.rb
<!DOCTYPE html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<title>Tippy.js CDN Sample</title>
<link rel="stylesheet" href="https://unpkg.com/tippy.js@6/dist/tippy.css">
</head>
<body>
<button id="myButton">ホバーしてね</button>
<!-- Popper.js -->
<script src="https://unpkg.com/@popperjs/core@2"></script>
<!-- Tippy.js -->
<script src="https://unpkg.com/tippy.js@6"></script>
<script>
tippy('#myButton', {
content: 'これはツールチップです！',
placement: 'top',
});
</script>
</body>
</html>