add mastodon profile verification

Author: atuttle

includes/head.html

@@ -39,3 +39,4 @@
 <link href="https://github.com/atuttle" rel="me" />
 <link rel="webmention" href="https://webmention.io/adamtuttle.codes/webmention" />
 <link rel="pingback" href="https://webmention.io/adamtuttle.codes/xmlrpc" />
+<link rel="me" href="https://jawns.club/@adamtuttle" />