Returns a $pages collection with all first-level children in the content folder
<nav class="main-menu" role="navigation">
<ul>
<?php foreach($site->children()->visible() as $item): ?>
<li><a<?php e($item->isOpen(), ' class="active"') ?> href="<?php echo $item->url() ?>"><?php echo html($item->title()) ?></a></li>
<?php endforeach ?>
</ul>
</nav>