seo: set basic OG and twitter meta tags

Author: avivace

theme/index.hbs

@@ -20,6 +20,16 @@
         <meta name="viewport" content="width=device-width, initial-scale=1">
         <meta name="theme-color" content="#ffffff" />
 
+        <!-- Open Graph tags-->
+        <meta name="og:site_name" content="summary" />
+        <meta name="og:image" content="https://gbdev.io/pandocs/favicon.png" />
+        <meta name="og:title" content="{{ title }}" />
+        <meta name="og:description" content="{{ description }}" />
+
+        <!-- Twitter meta tags -->
+        <meta name="twitter:card" content="summary" />
+        <meta name="twitter:site" content="@gbdev0" />
+
         {{#if favicon_svg}}
         <link rel="icon" href="{{ path_to_root }}favicon.svg">
         {{/if}}