In the past I have used Open Atrium 1 as an intranet site making use of the document management system.
I can't work out how to do something similar in OA2. From the documentation I have found:
News section - for document management, wikis, or articles
So I have created a News section. It looks like I can create a Document Page and add attachments to it. Do I no longer have the options to create files and folders. Just document pages and attachments?