jingle-content-category ProtoXEP: Fix indentation in example

We traditionally use two spaces for indentation in our XML examples.

Author: linkmauve

inbox/jingle-content-category.xml

@@ -98,7 +98,7 @@ a=content:speaker
 m=video 54132 RTP/AVP 31
 a=rtpmap:31 H261/9000
 a=content:sl
-        </code>
+</code>
 
         <p>Should then map to:</p>
 
@@ -112,26 +112,26 @@ a=content:sl
           initiator='stuart@studio.org/main'
           sid='a73sjjvkla37jfea'>
     <content creator="initiator" name='video0'>
-        <transport xmlns="urn:xmpp:jingle:transports:ice-udp:1"/>
-        <description xmlns="urn:xmpp:jingle:apps:rtp:1" media="video">
-            <category xmlns=']]>&namespace;<![CDATA[' name='slides'/>
-            <category xmlns=']]>&namespace;<![CDATA[' name='alt'/>
-            <payload-type id="31" name="H261" clockrate="9000"/>
-        </description>
+      <transport xmlns="urn:xmpp:jingle:transports:ice-udp:1"/>
+      <description xmlns="urn:xmpp:jingle:apps:rtp:1" media="video">
+        <category xmlns=']]>&namespace;<![CDATA[' name='slides'/>
+        <category xmlns=']]>&namespace;<![CDATA[' name='alt'/>
+        <payload-type id="31" name="H261" clockrate="9000"/>
+      </description>
     </content>
     <content creator="initiator" name='video1'>
-        <transport xmlns="urn:xmpp:jingle:transports:ice-udp:1"/>
-        <description xmlns="urn:xmpp:jingle:apps:rtp:1" media="video">
-            <category xmlns=']]>&namespace;<![CDATA[' name='speaker'/>
-            <payload-type id="31" name="H261" clockrate="9000"/>
-        </description>
+      <transport xmlns="urn:xmpp:jingle:transports:ice-udp:1"/>
+      <description xmlns="urn:xmpp:jingle:apps:rtp:1" media="video">
+        <category xmlns=']]>&namespace;<![CDATA[' name='speaker'/>
+        <payload-type id="31" name="H261" clockrate="9000"/>
+      </description>
     </content>
     <content creator="initiator" name='video2'>
-        <transport xmlns="urn:xmpp:jingle:transports:ice-udp:1"/>
-        <description xmlns="urn:xmpp:jingle:apps:rtp:1" media="video">
-            <category xmlns=']]>&namespace;<![CDATA[' name='sl'/>
-            <payload-type id="31" name="H261" clockrate="9000"/>
-        </description>
+      <transport xmlns="urn:xmpp:jingle:transports:ice-udp:1"/>
+      <description xmlns="urn:xmpp:jingle:apps:rtp:1" media="video">
+        <category xmlns=']]>&namespace;<![CDATA[' name='sl'/>
+        <payload-type id="31" name="H261" clockrate="9000"/>
+      </description>
     </content>
   </jingle>
 </iq>