Vanilla Javascript로 가상돔(VirtualDOM) 만들기

https://junilhwang.github.io/TIL/Javascript/Design/Vanilla-JS-Virtual-DOM/#_1-%E1%84%87%E1%85%B3%E1%84%85%E1%85%A1%E1%84%8B%E1%85%AE%E1%84%8C%E1%85%A5-%E1%84%85%E1%85%A9%E1%84%83%E1%85%B5%E1%86%BC-%E1%84%80%E1%85%AA%E1%84%8C%E1%85%A5%E1%86%BC