Subcontractor contract upload to TeamLink

It would be useful for subcontractors using the TeamLink to be able to upload signed contracts back into the Linked Files section of the Subcontracts module. Currently it seems that functionality is limited to users using Docusign. For people using other methods of e-Sign, it would be helpful just for them to be able to sign outside of TeamLink and re-upload the signed document back into a Linked Files section. Right now they are having to email it back to us.