Added admonition for author and revision order.

src/docs/asciidoc/wiki/wiki_header.adoc

@@ -30,6 +30,11 @@ Mandatory. Title of your document.
 
 Optional. Document author.
 
+[IMPORTANT]
+====
+Optional Author and Revision information immediately follows the header title.
+====
+
 == :revnumber:
 
 Optional. Revision number.