Add a slide called Commits

I'll be providing a link to this commit as an example
Add a slide for the command line

We still need to produce the background image, I'm hoping that this activitiy
I'm doing write now should produce a nice image.
Add command line background image
Add a slide about git gui
Gitk is on a separate slide
Add gitk and git gui screenshots
Move git tools and clients to the right section
Add some git basics slides
Add branching image
Describe a basic workflow
Merge branch 'concepts' into gh-pages
Add a slide for github for mac
Add the intellij blame screenshot
Link to other clients
Merge branch 'clients' into gh-pages
Section on Github
Add link to Atlassian tutorial
Add important xckd graphic
Spacing on atlassian tutorials link
Add my email address