add og meta tags

Author: gildesmarais

_includes/head_custom.html

@@ -1,10 +1,20 @@
+<meta name="mobile-web-app-capable" content="yes">
 <meta name="apple-mobile-web-app-capable" content="yes">
 <meta name="apple-mobile-web-app-status-bar-style" content="black">
 <meta name="referrer" content="no-referrer" />
+<meta name="description" content="{% if page.description %}{{ page.description | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
 <meta
   name="robots"
   content="{% if page.noindex %}noindex, noarchive, follow{% else %}index, follow{% endif %}"
 />
+
+<meta property="og:url" content="{{ page.url | replace:'index.html','' | absolute_url }}">
+<meta property="og:title" content="{% if page.title %}{{ page.title }}{% else %}{{ site.title }}{% endif %}">
+<meta property="og:description" content="{% if page.description %}{{ page.description | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
+<meta property="og:site_name" content="{{ site.title }}">
+<meta property="og:image" content="{{ '/assets/images/logo.png' | absolute_url }}">
+<meta property="og:type" content="website">
+
 <link rel="stylesheet" href="{{ '/assets/css/main.css' | relative_url }}" />
 <link rel="apple-touch-icon" sizes="180x180" href="/assets/images/apple-touch-icon.png">
 <link rel="icon" type="image/png" sizes="32x32" href="/assets/images/favicon-32x32.png">