home: vim: migrate to 'gruvbox-nvim'

I think this one will be more up-to-date with NeoVim evolutions, like
LSP semantic tokens.

home/vim/default.nix

@@ -35,7 +35,7 @@ in
 
     plugins = with pkgs.vimPlugins; [
       # Theming
-      vim-gruvbox8 # Nice dark theme
+      gruvbox-nvim # Nice dark theme
       lualine-nvim # A lua-based status line
       lualine-lsp-progress # Show progress for LSP servers
 

home/vim/init.vim

@@ -81,14 +81,10 @@ set mouse=
 " Set dark mode by default
 set background=dark
 
-" Include plug-in integration
-let g:gruvbox_plugin_hi_groups=1
-" Include filetype integration
-let g:gruvbox_filetype_hi_groups=1
 " 24 bit colors
 set termguicolors
 " Use my preferred colorscheme
-colorscheme gruvbox8
+colorscheme gruvbox
 " }}}
 
 " Search parameters {{{