A PDF is a versatile format. In addition to all the ways you can modify the file, you can also use it as a storage container. You can attach other files to it which can be extracted at a later time. 

Click the Extras panel icon located on the right-hand side of the application window, then click the Paperclip icon to open the Attachments section.

You can add any attachments by clicking on Add or Plus icon. This will open a Browse​ window allowing you to go through your computer looking for files to attach. 

You can right-click on an attached file to Open, Save, or Delete it. 

Click here to type a file description.