chore: flatten module structure

modules/image/veritysetup.nix

@@ -0,0 +1,39 @@
+{ config, lib, ... }:
+{
+
+  options.boot.initrd.systemd.root = lib.mkOption {
+    type = lib.types.enum [
+      "fstab"
+      "gpt-auto"
+      ""
+    ];
+  };
+
+  config.boot.initrd = {
+
+    kernelModules = [
+      "dm_mod"
+      "dm_verity"
+    ];
+
+    systemd = {
+
+      # Required to activate systemd-fstab-generator
+      root = "";
+
+      additionalUpstreamUnits = [
+        "veritysetup-pre.target"
+        "veritysetup.target"
+        "remote-veritysetup.target"
+      ];
+
+      storePaths = [
+        "${config.boot.initrd.systemd.package}/lib/systemd/systemd-veritysetup"
+        "${config.boot.initrd.systemd.package}/lib/systemd/system-generators/systemd-veritysetup-generator"
+      ];
+
+    };
+
+  };
+
+}