Make neovim the default editor.

Remember to exit the current session before you'll see the changes, even
after `nixos-rebuild switch`.

nalai/etc/nixos/configuration.nix

@@ -95,6 +95,10 @@
   # Install firefox.
   programs.firefox.enable = true;
 
+  # Set neovim as the default editor
+  programs.neovim.enable = true;
+  programs.neovim.defaultEditor = true;
+
   # List packages installed in system profile. To search, run:
   # $ nix search wget
   environment.systemPackages = with pkgs; [