bootstrap 4 basic structure
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<html lang="en">
<head>
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<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
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<title>Hello, world!</title>
</head>
<body>
<h1>Hello, world!</h1>
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<!-- Option 1: jQuery and Bootstrap Bundle (includes Popper) -->
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