make configuration.nix host agnostic and add nix-conv

flake.nix

@@ -31,6 +31,17 @@
 	  ./users/shatteredmint.nix
 	];
       };
+
+      nix-conv = lib.nixosSystem {
+        system = "x86_64-linux";
+        specialArgs = inputs;
+
+        modules = [
+          ./configuration.nix
+          ./plasma.nix
+          ./users/shatteredmint.nix
+        ];
+      };
     };
   };
 }