make a working example

Author: fricklerhandwerk

docs/howtos/use-without-flakes.md

@@ -6,16 +6,29 @@ in your NixOS configuration and define disko devices as described in the
 [examples](https://github.com/nix-community/disko/tree/master/example).
 
 Let's assume that your NixOS configuration lives in `configuration.nix` and your
-target machine is called `machine`.
+target machine is called `machine`:
 
 ```nix
 # configuration.nix
 {
-  pkgs ? import (fetchTarball channel:nixos-24.05) {};
+  sources ? {
+    nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-24.05";
+    disko = fetchTarball "https://github.com/nix-community/disko/tarball/v1.6.1";
+  },
+  system ? builtins.currentSystem,
+  pkgs ? import sources.nixpkgs { inherit system; config = {}; overlays = []; },
 }:
-{
-  config = { config, pkgs, ... }: { /* ... */ };
+rec {
   machine = pkgs.nixos config;
+  config = { config, pkgs, ... }: {
+    system.stateVersion = "24.05";
+    imports = [
+      "${sources.disko}/module.nix"
+      "${sources.disko}/example/hybrid.nix"
+    ];
+    disko.devices.disk.main.device = "/dev/sda";
+    boot.loader.systemd-boot.enable = true;
+  };
 }
 ```