app/app.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Plotly Desktop Connector</title>
    <link rel="stylesheet" href="../node_modules/font-awesome/css/font-awesome.min.css" />
    <script>
    (function() {
        if (!process.env.HOT) {
            const link = document.createElement('link');
            link.rel = 'stylesheet';
            link.href = '../dist/style.css';
            document.write(link.outerHTML);
        }
    }());
    </script>
</head>
<body>
    <link rel="stylesheet" type="text/css" href="./components/Settings/DatabaseDropdown/react-select.css">
    <link href='https://fonts.googleapis.com/css?family=Open+Sans:400,300,600' rel='stylesheet' type='text/css'>
    <div id="root"></div>
    <script>
    (function() {
        const script = document.createElement('script');
        script.src = (process.env.HOT) ? 'http://localhost:3000/dist/bundle.js' : '../dist/bundle.js';
        document.write(script.outerHTML);
    }());
    </script>
</body>
</html>