You are able to attach files to a contact record. You do this via the Documents area.
When you click on Documents it will bring up a list of correspondence along with an area where you can Attach a file. Within this section, it tells you to either drag the file or click to navigate to a folder and then upload.
Once you upload the file it appears in the document history. For my example, I have uploaded a word document called Consent Form.
When I click View it downloads the file allowing me to open and view it.