<!DOCTYPE html>
<html>
    <head>
    </head>
    <body>
        <h1>Teams</h1>
        <hr>

        <table class="table">
            <tr>
                <th>Lp.</th>
                <th>Code</th>
                <th>Team</th>
            </tr>
            {% for team in teams %}
                <tr>
                    <td>{{loop.index}}</td>
                    <td>{{team.key}}</td>
                    <td>{{team.title}}</td>
                </tr>
            {% endfor %}
        </table>
    </body>
</html>
<!DOCTYPE html>
<html>
    <head>
        <link href="/bootstrap/css/bootstrap.css" rel="stylesheet" >
    </head>
    <body>
        <h1>Teams</h1>
        <hr>

        <table class="table">
            <tr>
                <th>Lp.</th>
                <th>Code</th>
                <th>Team</th>
            </tr>
            {% for team in teams %}
                <tr>
                    <td>{{loop.index}}</td>
                    <td>{{team.key}}</td>
                    <td>{{team.title}}</td>
                </tr>
            {% endfor %}
        </table>
    </body>
    <footer>
        <script src="/bootstrap/js/bootstrap.min.js"></script>
    </footer>
</html>
Add bootstrap css and js to twig template
Add bootstrap css and js to twig template