pinwheel: Add postman module

hosts/pinwheel/modules/postman/default.nix

@@ -0,0 +1,20 @@
+{ pkgs, ... }:
+{
+  nixpkgs.overlays = [
+    (final: prev: {
+      postman = prev.postman.overrideAttrs(old: rec {
+        version = "20230716100528";
+        src = final.fetchurl {
+          url = "https://web.archive.org/web/${version}/https://dl.pstmn.io/download/latest/linux_64";
+          sha256 = "sha256-svk60K4pZh0qRdx9+5OUTu0xgGXMhqvQTGTcmqBOMq8=";
+
+          name = "${old.pname}-${version}.tar.gz";
+        };
+      });
+    })
+  ];
+
+  home-manager.users.alex = {
+    home.packages = [ pkgs.postman ];
+  };
+}