i don't really like TortoiseGit. Although it does helps in some ways, but now i really can't get it to work. kept on giving me "No Authorization method found.. " error or whatever. but that is not important. since we are in the subject about converting rAthena to git.
i might just as offer this https://bitbucket.org/hafizbistar/rathena
i know i use bitbucket instead of github, but what can i say, i needed the private repo
have fun.
note: Someone did the same on Github, but his last update was early June. I believe he did a full history convert like i did.