add instructions for ca_request hostname

SETUP.md

@@ -2,7 +2,7 @@ SETUP
 =========
 
 1. Copy `group_vars/all.yaml.example` to `group_vars/all.yaml`
-2. Fill `all.yaml` with the gateway hostname and the content of the `user_ca_key`
+2. Fill `group_vars/all.yaml` with the gateway hostname and the content of the `user_ca_key`
 3. Add the gateway hostname to `inventory`, set `ansible_host` and `ansible_user`
 4. Add the ca hostname to `inventory`, set `ansible_host` and `ansible_user`
-
+5. Add the ca\_request hostname to `inventory`, set `ansible_host` and `ansible_user`