Address TA feedback: Store images in the wiki repo

[nbhuiyan]

Here is what Sina wanted us to address:

The image files that you use in your wikis should be put inside the wiki repository not the main one. Also the images in your Markdown files should be referenced by their relative paths e.g. doc/img.jpg

The URL for cloning the wiki repository is as follows:

https://github.com/<organization_name>/<project_name>.wiki.git

Regards,
Sina

[nbhuiyan]

Done