JGive: How to upload a 'Campaign' related document?

I have a need to make a provision for the person launching a campaign to be able to upload a 'Campaign' related document like a 'Business Plan'. I have searched the features available but could not find a way add this type of field. The only upload feature available is for images. I am not sure if such a feature is already available and I could not find it. Kindly advise how I can achieve this.