Add note on nvim plugin dir

nvim/init.vim

@@ -2,6 +2,8 @@ set nocompatible
 filetype off
 
 " Plugins
+" Note: on most systems, this will make the plugins reside in \
+" ~/.local/share/nvim/plugged/
 let data_dir = has('nvim') ? stdpath('data') . '/site' : '~/.vim'
 if empty(glob(data_dir . '/autoload/plug.vim'))
   silent execute '!curl -fLo '.data_dir.'/autoload/plug.vim --create-dirs  https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim'