There are various ways to add a picture on GitHub. This is how I do it.
Instructions:
1. Upload your picture to a hosting site.
2. Copy the URL assigned to the picture
3. Go to the file on GitHub; in which, you want the picture included.
4. Edit the file with this code...

5. Preview (if desired) and commit.
Music in the video...
Title: Victory
Artist: Unknown
The track was taken from the YouTube channel "Music for Video Library"
• ROYALTY FREE Epic Victory Music Royal...