Check out this video for a full walkthrough!
There are two ways to add a document (or upload an image) to your note:
1- Click 'Attach Files' from the drop down menu in your 1-on-1. This allows you to search through your files and choose the one you would like to add.
2- Drag and drop the document from your desktop or a file into the note.
The document will appear at the bottom of the note under 'Attachments.'