Tangent: I see example.jpg added to the main repo, just for the readme. If you don't want to store binary blobs, there's an alternative: open a new issue, then copy-paste the image into the issue. It'll give you a link that you can use in a readme permanently.
It won't, but it will still be displayed when rendering the readme, just like if it were hosted on any other webserver. Of course only as long as the webserver is around, but still better than adding several MB to your repo just for a few screenshots.