Add snippet to create a nix shell

lua/plugins.lua

@@ -153,7 +153,8 @@ local plugins = {
             "rafamadriz/friendly-snippets",
           },
           init = function()
-            require("luasnip.loaders.from_vscode").lazy_load()
+            -- require("luasnip.loaders.from_vscode").lazy_load()
+            require("luasnip.loaders.from_snipmate").lazy_load()
           end
 
         },

snippets/nix.snippets

@@ -0,0 +1,8 @@
+
+snippet shell nix-shell
+	{ pkgs ? import <nixpkgs> {} }:
+		pkgs.mkShell {
+			buildInputs = with pkgs; [ 
+				$1
+			];
+		}