[math4] Small Muthris Update

[Doug]

I had to do a presentation on the overall project, so I committed it to
the code base in the docs folder.  Since school has started up again, I
don't have free time to continue working on the project.  However, I
believe I should increase my Python experience before graduation and
working on Muthris is a good way to do that.  But I don't know when that
will happen...

Someone asked for a few screenshots.  I posted one on Muthris' project
page (http://git.sugarlabs.org/projects/muthris).   It's all textual
menus at the moment, so I think only one image is good enough.

For the new students, if you want to work on the project I can make the
time to help you get up to speed on it.