There are two ways you can add your resume to Portfolio. The first would be to add your content to a custom page as an image or an embed.
The second option is to use Dropbox to create a downloadable PDF and add it to a link page on Portfolio.
Head over to the toolbar on the left hand side and click the "+" Add Content icon (or click the "+" icon in the lower right of Manage Content) > Link.
Upload your file to Dropbox, and when it has completed, click "share" and copy the link provided.