[Feature request] add ability to upload images/jpg to github issues

[alphaCTzo7G]

Its very useful to upload/add text to github issues. What I have been using recently is to update the issues with static or dynamic gif images, so as to capture visually what happened. This allows you to capture more information that can be sometimes provided over written text.

It would be very helpful if I could add a image file name in the issues, and if ghi automatically parsed it and uploaded the file to github.