fix: add slides about gitkraken#3

cmgriffing-at-gitkraken wants to merge 1 commit intomaincmgriffing-at-gitkraken/presentation-libgit2-nodegit-native-git-oh-my:mainfrom

add-gitkraken-slidescmgriffing-at-gitkraken/presentation-libgit2-nodegit-native-git-oh-my:add-gitkraken-slidesCopy head branch name to clipboard