Create a sculpin dev shell

Signed-off-by: Oliver Davies <oliver@oliverdavies.uk>

flake.nix

@@ -12,6 +12,7 @@
         buildNpmPackage
         fetchFromGitHub
         mkShell
+        php
         ;
     in
     {
@@ -23,6 +24,10 @@
         openapi-mock = import ./openapi-mock.nix {
           inherit buildGoModule fetchFromGitHub;
         };
+
+        sculpin = import ./sculpin.nix {
+          inherit fetchFromGitHub php;
+        };
       };
 
       devShells.${system} = with pkgs; {
@@ -45,6 +50,12 @@
             self.packages.${system}.openapi-mock
           ];
         };
+
+        sculpin = mkShell {
+          packages = [
+            self.packages.${system}.sculpin
+          ];
+        };
       };
     };
 }