How Do I get Document and Completion Certificate into one pdf file after completing the all steps of workflow

I hope there is a way to print both my DocuSign envelope contents and the certification (certificate) in one PDF document.  This would be immensely helpful to my company, and a great timesaver and make sure that the certificate for each DocuSign accompanies its document.
When we complete the document → two pdf is generated first is completed document and second is completion certificate. I want these both pdfs into one pdf, how to achieve this in CLM. 
I don’t want two pdfs getting generated after completion of document.

The ability to put the document and certificate into a single PDF by a click of a button on screen would be a great timesaver and ensure that the certification is saved for each document.

Please share If you have any solution on this.