fix: you need to re-login after usermod

docs/operators/tutorial.md

@@ -38,6 +38,10 @@ wget -O- https://get.docker.com | bash
 # add user to docker group
 sudo usermod -aG docker $USER
 
+# exit and re-login to load the group
+exit
+ssh <server-domain>
+
 # setup swarm
 docker swarm init
 docker network create -d overlay proxy