Update readme file 

1. Change comment guide rule 
 - comment must be written in ENGLISH
2. Change Indentation rule 
https://github.com/GDG-Korea/gdg_codelab_1403/issues/35 ,  https://github.com/GDG-Korea/gdg_codelab_1403/issues/54
 - Follow the original coding convention. (Tab=5space)
3. Add English readme file 
https://github.com/GDG-Korea/gdg_codelab_1403/issues/30