aria-current=“page”

Fixes #47

site/snippets/header.php

@@ -78,7 +78,7 @@
       */
       ?>
       <?php foreach ($site->children()->listed() as $item): ?>
-      <a <?php e($item->isOpen(), 'aria-current ') ?> href="<?= $item->url() ?>"><?= $item->title()->esc() ?></a>
+      <a <?php e($item->isOpen(), 'aria-current="page"') ?> href="<?= $item->url() ?>"><?= $item->title()->esc() ?></a>
       <?php endforeach ?>
       <?php snippet('social') ?>
     </nav>