if ~/.emacs exist init.el is not working.

reference link: http:https://seorenn.blogspot.kr/2013/02/emacs-elpamelpamarmalade.html

M-x pakage-install [ret] projectile [ret]

M-x projectile-mode [ret] find file: C-c p f

M-x package-install [ret] markdown [ret] sudo apt-get install markdown [ret]

M-x markdown-mode preview: C-c C-c p