Minor bug about.html. Show subtitle

Before it showed the description under the title, the description is used for meta tags, on this page the subtitle should be displayed under the title.

_layouts/about.html

@@ -8,7 +8,7 @@
           <h1 class="post-title">
            {% if site.title == "blank" -%}<span class="font-weight-bold">{{ site.first_name }}</span> {{ site.middle_name }} {{ site.last_name }}{%- else -%}{{ site.title }}{%- endif %}
           </h1>
-          <p class="desc">{{ page.description }}</p>
+          <p class="desc">{{ page.subtitle }}</p>
         </header>
 
         <article>