Returns a $files collection with all files in the page's directory.
<h2>Files</h2>
<ul>
<?php foreach($page->files() as $file): ?>
<li>
<a href="<?php echo $file->url() ?>">
<?php echo $file->filename() ?>
(<?php echo $file->niceSize() ?>)
</a>
</li>
<?php endforeach ?>
</ul>