<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>The Sample Page</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="/styles/style.css">
  </head>
  <body>
    <p>This is just test.</p>
  </body>
</html>

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>The Sample Page</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="/styles/style.css">
  </head>
  <body>
    <p>This is just test.</p>
    <script src="/scripts/main.js" defer async></script>
  </body>
</html>

Load JavaScript on the basic HTML template
[modify] Load JavaScript on the basic HTML template

