host-meta for the authority to enable discovery of pubkey serving

authority/static/.well-known/host-meta

+<?xml version='1.0' encoding='UTF-8'?>
+
+<XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0' 
+     xmlns:hm='http://host-meta.net/xrd/1.0'>
+
+  <hm:Host xmlns='http://host-meta.net/xrd/1.0'>127.0.0.1:56080</hm:Host>
+
+  <Link rel='lrdd' template='http://authority.mozilla.org/users/{uri}.xml'></Link>
+
+  <Link rel='other' value='something-different'></Link>
+</XRD>