Move application ExternalIVR static documentation to the new AstXML form.

(issue #15245)
Reported by: eliel
Patches:
      app_externalivr.diff uploaded by eliel (license 64)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@199514 65c4cc65-6c06-0410-ace0-fbb531ad65f3