Attaching a File
To attach a file to a page, navigate to the page settings by left clicking the setting symbol located in the page navigation dropdown or alternatively by using the keyboard shortcut ⌥+⌘+P.
At the bottom of the Page settings sub-window you will see a small list with the title Header File Attachments. To the right of the title there are two buttons, one marked with a – symbol and one marked with a + symbol. To add an attachment left click the button marked with a + and to remove an attachment left click the button marked with a –.