Update artifacts docs

POPETS-ARTIFACTS-README.md

@@ -76,7 +76,24 @@ This description is essential if you rely on proprietary software or software th
 Describe how the reviewer can obtain and install all third-party software, data sets, and models.
 -->
 #### Artifact 1-3
-Ordinary linux machine with docker engine installed.
+Ordinary linux machine with docker engine installed and
+[manageable as a non-root user](https://docs.docker.com/engine/install/linux-postinstall/#manage-docker-as-a-non-root-user).
+
+Please make sure your user (`$USER`) is part of the `docker` group.
+
+You can do so by running the following commands:
+
+```shell
+sudo groupadd docker
+sudo usermod -aG docker $USER
+newgrp docker
+```
+
+Test the docker command without sudo:
+
+```shell
+docker run hello-world
+```
 
 <!-- #### Artifact 4: Tracing attacks on SNIP-20 transfers
 Ordinary linux machine with docker engine installed to build the binaries and an
@@ -212,6 +229,27 @@ Use code segments to simplify the workflow, e.g.,
 python envtest.py
 ```
 -->
+
+Make sure your user (`$USER`) is part of the `docker` group.
+
+```shell
+getent group docker | grep $USER
+```
+
+If not, then add your user to the docker group:
+
+```shell
+sudo groupadd docker
+sudo usermod -aG docker $USER
+newgrp docker
+```
+
+Test the docker command without sudo:
+
+```shell
+docker run hello-world
+```
+
 Check docker version:
 
 ```shell
@@ -226,7 +264,7 @@ Make sure the docker compose command is available:
 docker compose
 ```
 
-Check that *only* node-2 is running 
+Check that *only* node-2 is running
 ```shell
 docker ps | grep hacking-localsecret-2-1
 ```