Add fediverse:creator meta tag

Author: jwheare

_layouts/default.html

@@ -19,6 +19,7 @@
 
     <meta name="author" content="IRCv3 Working Group">
     <meta name="description" content="{% if page.meta-description %}{{ page.meta-description }}{% else %}IRCv3 Development Community{% endif %}">
+    <meta name="fediverse:creator" content="@[email protected]">
 
     <link rel="alternate" type="application/rss+xml" href="{{ site.baseurl }}/feed.xml" />