icingaweb2/modules/doc/application/views/scripts/module/view.phtml

<?php if ($html === null): ?>
    <p>No documentation available.</p>
<?php else: ?>
<div class="row">
    <div class="col-sm-12 col-xs-12 col-md-2 col-lg-2">
        <?= $this->partial(
            'layout/menu.phtml',
            'default',
            array(
                'items' => $toc->getChildren(),
                'sub'   => false,
                'url'   => ''
            )
        );
        ?>
    </div>
    <div class="col-sm-12 col-xs-12 col-md-10 col-lg-10">
        <?= $html ?>
    </div>
</div>
<?php endif ?>