add list of resources for more git stuffs
change submodule reveal to reveal.js

* updated submodule to current version
* received error: submodule reference is not a tree
clarify ice breaker question
add git installation address to slide
remove redundant step from make a commit
add section with link to all Git GUIs

* gitk doesn't exist on my computer
removed strange command

* why is changing a file a command?
clarify git rm command
remove redundant section about reset
clarify header: committed not staged changes
whitespace: fix indentation
remove subsections (fix indentation)

* remembering to use the down arrow to navigate was too confusing
Merge pull request #1 from johnsons531/master

it's a start
add terminal note for windows users
add slide distinguishing Git vs Github
github slide updates with links to open source projects, new screenshots
Merge pull request #2 from johnsons531/master

add terminal note for windows users
Merge branch 'master' of github.com:cfarm/gdi-core-git-github