add instructions for working DNS in local molecule

Author: sjpb

molecule/README.md

@@ -29,10 +29,11 @@ test14 | 1            | N                       | As for #5 but also tests `extr
 Local installation on a RockyLinux 8.x machine looks like:
 
     sudo dnf install -y podman
+    sudo dnf install podman-plugins # required for DNS
     sudo yum install -y git
     git clone [email protected]:stackhpc/ansible-role-openhpc.git
     cd ansible-role-openhpc/
-    python3.8 -m venv venv
+    python3.9 -m venv venv
     . venv/bin/activate
     pip install -U pip
     pip install -r molecule/requirements.txt