XEP-0002: Fix minor DTD issues

xep-0002.xml

@@ -17,6 +17,7 @@
   <dependencies/>
   <supersedes/>
   <supersededby/>
+  <shortname>N/A</shortname>
   &stpeter;
   <revision>
     <version>1.1</version>

xep.dtd

@@ -118,7 +118,7 @@ THE SOFTWARE.
 <!ATTLIST img src CDATA '' >
 <!ELEMENT link (#PCDATA)* >
 <!ATTLIST link url CDATA '' >
-<!ELEMENT note (#PCDATA | link | tt | dfn | em | strong | cite | span)* >
+<!ELEMENT note (#PCDATA | link | tt | dfn | em | strong | cite | span | note)* >
 <!ELEMENT example (#PCDATA)* >
 <!ATTLIST example caption CDATA '' >
 <!ELEMENT code (#PCDATA | span | em)* >