README.md

@@ -264,6 +264,14 @@ Now, run required system setup (installs docker and laconic-so):
 zenith-ansible -i ./inventories/development/hosts.yml ./stage1-site.yml -e "mode=system-setup" -K --skip-tags onboarding
 ```
 
+If your machine did not have Docker installed before, the above command will install it. On Ubuntu, you will need to activate the `docker` group for your current shell:
+
+```bash
+newgrp docker
+```
+
+This is a one time operation required to be performed after installing docker.
+
 Setup the deployment directories and pull required docker images to generate base genesis file along with other artifacts:
 
 ```bash