Add image and author metadata

Signed-off-by: trivernis <trivernis@protonmail.com>

_includes/head.html

@@ -4,14 +4,19 @@
     <meta name="viewport" content="width=device-width, initial-scale=1">
 
     <title>{% if page.title %}{{ page.title | escape }}{% else %}{{ site.title | escape }}{% endif %}</title>
-  <meta name="description" content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
+    <meta name="author" content="{% if page.author%}{{ page.author | escape }}{% else %}{{ site.github_username | escape }}{% endif %}">
+    <meta name="description"
+        content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
+    <meta name="og:image"
+        content="{% if page.image %}{{ page.image }}{% else %}{{ '/assets/images/icon.png' }}{% endif %}">
+    {% assign user_url=site.url | append: site.baseurl %}
+    {% assign full_base_url=user_url | default: site.github.url %}
 
-  {% assign user_url = site.url | append: site.baseurl %}
-  {% assign full_base_url = user_url | default: site.github.url %}
     <link rel="stylesheet" href="{{ "/assets/style.css" | prepend: full_base_url }}">
 
     <link rel="canonical" href="{{ page.url | replace:'index.html','' | prepend: site.baseurl | prepend: site.url }}">
-  <link rel="alternate" type="application/rss+xml" title="{{ site.title }}" href="{{ "/feed.xml" | prepend: site.baseurl | prepend: site.url }}">
+    <link rel="alternate" type="application/rss+xml" title="{{ site.title }}" href="{{ " /feed.xml" | prepend:
+        site.baseurl | prepend: site.url }}">
 
     <script async defer src="https://buttons.github.io/buttons.js"></script>
 </head>