https://backlog.com/git-tutorial/kr/intro/intro1_1.html
https://geonlee.tistory.com/m/206
https://milooy.wordpress.com/2016/07/02/daily-commit-1-year/ https://milooy.wordpress.com/2015/10/08/daily-commit/
https://geonlee.tistory.com/190
https://ryan-han.com/post/dev/gitflow/