Formalize <podcast:txt> tag

docs/1.0.md

@@ -1019,6 +1019,7 @@ like [SPF](https://en.wikipedia.org/wiki/Sender_Policy_Framework#Implementation)
 ### Purposes
 The following are a list of strings known to be in common use. This list is in no way exhaustive. As new purposes come into
 common use, this list will be updated by the community to reflect that.
+
 - `verify` - The node value is expected to contain a string that is given by a third party platform to a podcaster in 
              order to prove that they are the owner of the feed and are in control of it.  This is meant to replace the 
              need for emails to exist in feeds.