Add og's required properties.

Author: exoego

_includes/headertop.html

@@ -13,6 +13,8 @@
     <meta name="viewport" content="width=device-width, initial-scale=1">
 
     <meta property="og:site_name" content="{{ site.title }}"/>
+    <meta property="og:type" content="{% if page.url == '/' %}website{% else %}article{% endif %}"/>
+    <meta property="og:image" content="{{ site.url }}/resources/img/scala-spiral-3d-2-toned-down.png"/>
     {% if page.title %}<meta property="og:title" content="{{ page.title }}"/>{% endif %}
     {% if page.description %}<meta property="og:description" content="{{ page.description }}"{% endif %}