Apparently, the APIHelp generator in Zope 2.12 is pickier. Interface files need a top-level docstring with an empty first line to serve as title of the document

git-svn-id: https://svn.erp5.org/repos/public/erp5/sandbox/portal_types@29491 20353a03-c40f-0410-a6d1-a30d3c3de9de