# Filetype detection

vim files under these directories:
ftplugin/FT.vim
ftplugin/FT_.vim
ftplugin/FT/*.vim'
will be loaded with the filetype FT.

## Reference
http://learnvimscriptthehardway.stevelosh.com/chapters/44.html
https://www.reddit.com/r/vim/comments/4p4ogb/augroup_autocmd_need_some_clarification/
/usr/share/vim/vim81/ftplugin.vim
:help new-filetype
:help setf  # set filetype