vim: Add nix file type plugin

home/.config/nvim/init.vim

@@ -94,6 +94,7 @@ Plug 'ntpeters/vim-better-whitespace'
 
 " Syntax highlighting/Language support
 Plug 'Glench/Vim-Jinja2-Syntax', { 'for': 'jinja' }
+Plug 'LnL7/vim-nix', { 'for': 'nix' }
 Plug 'cespare/vim-toml', { 'for': 'toml' }
 Plug 'mechatroner/rainbow_csv'
 Plug 'posva/vim-vue', { 'for': 'vue' }