add cs-demo-manager appimage package, and group with postgresql for cs-tools module.

modules/nixos/cs-tools/default.nix

@@ -0,0 +1,24 @@
+{ lib, pkgs, config, namespace, ... }:
+
+let
+  cfg = config.${namespace}.cs-tools;
+in
+{
+  options.${namespace}.cs-tools = {
+    enable = lib.mkEnableOption "CS tools including CS Demo Manager and PostgreSQL";
+  };
+
+  config = lib.mkIf cfg.enable {
+    services.postgresql = {
+      enable = true;
+      ensureDatabases = [ "csdm" ];
+      ensureUsers = [{
+        name = "csdm";
+      }];
+    };
+    environment.systemPackages = with pkgs; [
+      my-namespace.cs-demo-manager
+      postgresql
+    ];
+  };
+}