makeInitrdNG: add meta and update script

pkgs/build-support/kernel/make-initrd-ng-tool.nix

@@ -6,4 +6,12 @@ rustPlatform.buildRustPackage {
 
   src = ./make-initrd-ng;
   cargoLock.lockFile = ./make-initrd-ng/Cargo.lock;
+
+  passthru.updateScript = ./make-initrd-ng/update.sh;
+
+  meta = {
+    description = "Tool for copying binaries and their dependencies";
+    maintainers = with lib.maintainers; [ das_j elvishjerricco k900 lheckemann ];
+    license = lib.licenses.mit;
+  };
 }

pkgs/build-support/kernel/make-initrd-ng/update.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -p cargo -i bash
+cd "$(dirname "$0")"
+cargo update