This feature is available to users with a SOLO licence.
Adding a document as an attachment can be useful to preserve legibility on large spreadsheet files and other documents. To start, add the document to your bundle and open the "Document properties" by clicking the three dot menu and selecting "Properties".
With the "Document properties" open, you can use the "Add file as attachment" toggle.
When the document is added as an attachment, you will see a small yellow paperclip added to the icon in the documents list; this indicates that this document will be added as an attachment.
Once the bundle has been generated into a PDF, the documents which have been added as an attachment will still appear in your index - however, the document will be replaced with a hyperlinked page which will open up the document in the native app (such as Excel).
Note: Documents that cannot be displayed in a PDF format, such as video and audio files are automatically added to the bundle as attachments.