Documentation: Add docs for inline-diff undo feature.
Documentation: Add docs for inline-diff undo feature.

Relates to #35.

stoivo/GitSavvy,asfaltboy/GitSavvy,dvcrn/GitSavvy,ddevlin/GitSavvy,asfaltboy/GitSavvy,divmain/GitSavvy,jmanuel1/GitSavvy,asfaltboy/GitSavvy,ralic/GitSavvy,stoivo/GitSavvy,ddevlin/GitSavvy,jmanuel1/GitSavvy,stoivo/GitSavvy,ddevlin/GitSavvy,dreki/GitSavvy,dreki/GitSavvy,dvcrn/GitSavvy,divmain/GitSavvy,theiviaxx/GitSavvy,ralic/GitSavvy,theiviaxx/GitSavvy,divmain/GitSavvy