add next step

Author: tbrowder

CONTRIBUTING.md

@@ -71,6 +71,9 @@ filename, you can add the document by following these steps:
 + create a **filename.pod6** file in the **doc/Language** directory and
   ensure it adheres to the conventions in
   [CREATING-NEW-DOCS.md](writing-docs/CREATING-NEW-DOCS.md)
+  
++ create an entry for your new document in the Language directory's
+  [00-POD6-CONTROL](doc/Language/00-POD6-CONTROL) file
 
 ## Documenting types