setup: Fix ansible-playbook domain join command

* Correct example hostname
* Apply `base.yml` and `hostname.yml` separately, without
  `bootstrap.yml`, to avoid deploying *firewalld*
* Correct host IP address

setup/README.md

@@ -17,11 +17,12 @@ Add to *pyrocufflink.blue* domain:
 
 ```sh
 ansible-playbook \
-    -l k8s-amd64-ctrl0.pyrocufflink.blue \
+    -l k8s-ctrl0.pyrocufflink.blue \
     remount.yml \
-    bootstrap.yml \
+    base.yml \
+    hostname.yml \
     pyrocufflink.yml \
-    -e ansible_host=172.30.0.167/28 \
+    -e ansible_host=172.30.0.170 \
     -u root \
     -e @join.creds
 ```