pkgs/run-with-docker-group: Add script

pkgs/run-with-docker-group/default.nix

@@ -0,0 +1,6 @@
+{ pkgs, ... }:
+
+pkgs.writeShellApplication {
+  name = "run-with-docker-group";
+  text = builtins.readFile ./run-with-docker-group.sh;
+}

pkgs/run-with-docker-group/run-with-docker-group.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ $# -eq 0 ]]; then
+	set -- "${SHELL}"
+fi
+
+exec systemd-run \
+	"--property=User=$(id -un)" \
+	"--property=SupplementaryGroups=docker" \
+	"--pty" "--same-dir" "--wait" "--collect" "--service-type=exec" \
+	"--quiet" \
+	"$@"