Add theme flake.nix to add tailwindcss

flake.nix

@@ -1,8 +1,15 @@
 {
-  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  inputs={
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+
+    opdavies-theme = {
+      inputs.nixpkgs.follows = "nixpkgs";
+      url = "path:./themes/opdavies";
+    };
+  };
 
   outputs =
-    { nixpkgs, ... }:
+    { nixpkgs, opdavies-theme, ... }:
     let
       system = "x86_64-linux";
       pkgs = import nixpkgs { inherit system; };
@@ -17,13 +24,22 @@
     in
     {
       devShells.${system}.default = pkgs.mkShell {
+        inputsFrom = [
+          opdavies-theme.devShells.${system}.default
+        ];
+
         packages = with pkgs; [
           just
+          lua-language-server
+          lua54Packages.luacheck
+          nixd
           php
           phpactor
           phpPackages.composer
           sqlite
         ];
       };
+
+      formatter.${system} = pkgs.nixfmt-rfc-style;
     };
 }