Improve abstract and mention Web Host Metadata Link format

Author: adiaholic

xep-0156.xml

@@ -7,7 +7,7 @@
 <xep>
 <header>
   <title>Discovering Alternative XMPP Connection Methods</title>
-  <abstract>This document defines a DNS TXT Resource Record format for use in discovering alternative methods of connecting to an XMPP server.</abstract>
+  <abstract>This document defines an XMPP Extension Protocol for discovering alternative methods of connecting to an XMPP server using two ways: (1) DNS TXT Resource Record format; and (2) Web Host Metadata Link format.</abstract>
   &LEGALNOTICE;
   <number>0156</number>
   <status>Draft</status>