Add opengraph fields and other seo tweaks.

Author: rouilj

website/www/index.txt

@@ -1,6 +1,21 @@
 Roundup Issue Tracker
 =====================
 
+.. meta::
+   :title: Roundup Issue Tracker
+   :description: A simple-to-use and -install issue-tracking system
+       with command-line, web, REST, XML-RPC and e-mail interfaces.
+       Adaptable to many uses cases. Allows you to customise the look
+       and feel and implement different workflows.
+   :og:type: website
+   :og:url: https://www.roundup-tracker.org/
+   :og:title: Roundup Issue Tracker
+   :og:description: A simple-to-use and -install issue-tracking system
+       with command-line, web, REST, XML-RPC and e-mail interfaces.
+       Adaptable to many uses cases. Allows you to customise the look
+       and feel and implement different workflows.
+   :og:image: https://www.roundup-tracker.org/_images/index_logged_out.png
+
 .. raw:: html
 
    <div class="release_info note">Download: