<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Markdown in HTML</title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/showdown/2.1.0/showdown.min.js"></script>
</head>
<body>

    <div id="markdown">
        # Hello World  
        This is **Markdown** inside HTML.  
        - Item 1  
        - Item 2  
    </div>

    <script>
        var converter = new showdown.Converter();
        var markdownText = document.getElementById("markdown").innerText;
        document.getElementById("markdown").innerHTML = converter.makeHtml(markdownText);
    </script>

</body>
</html>