nvim: Switch to using nightfly theme

This theme has some better styled colors for Haskell and though
increases the load times in vim slightly seems better to use.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>

nvim/.config/nvim/init.vim

@@ -23,7 +23,7 @@ Plug 'thaerkh/vim-workspace'
 " Commenter
 Plug 'tpope/vim-commentary'
 " Theme
-Plug 'sickill/vim-monokai'
+Plug 'bluz71/vim-nightfly-guicolors'
 Plug 'justinmk/vim-syntax-extra'
 Plug 'octol/vim-cpp-enhanced-highlight'
 " Autoload and read from dish if file changes
@@ -186,8 +186,8 @@ set completeopt=menu,noselect,preview,noinsert
 set sessionoptions-=blank
 
 " Theme
-colorscheme monokai
 set background=dark
+colorscheme nightfly
 " Fixes colors in Neovim terminal
 highlight LineNr ctermbg=000
 
@@ -688,6 +688,9 @@ let g:vista_ctags_cmd = {
             \ 'haskell': 'stack exec -- hasktags -x -o - -c',
             \ }
 
+" Allow nightfly theme to set indentline colors
+let g:indentLine_setColors = 0
+
 " ----------------------------- Functions ------------------------------------
 function! NvimGdbNoTKeymaps()
   tnoremap <silent> <buffer> <Esc> <C-\><C-n>