fixed typo in page_hero (mmistakes#2428)

Author: chrismelman

_includes/page__hero.html

@@ -45,7 +45,7 @@ <h1 id="page-title" class="page__title" itemprop="headline">
       {% endif %}
     </div>
   {% else %}
-    <img src="{{ pade.header.image | relative_url }}" alt="{{ image_description }}" class="page__hero-image">
+    <img src="{{ page.header.image | relative_url }}" alt="{{ image_description }}" class="page__hero-image">
   {% endif %}
   {% if page.header.caption %}
     <span class="page__hero-caption">{{ page.header.caption | markdownify | remove: "<p>" | remove: "</p>" }}</span>