Apply suggestion to docs/installation_instructions.md

docs/installation_instructions.md

@@ -199,7 +199,7 @@ If you want your cluster to be reachable under the fully qualified domain name
 Create the OpenAppStack settings for your VPS by running the following command:
 
 ```
-$ python -m openappstack my-cluster create --ip-address IP_ADDRESS --subdomain oas example.org
+$ python -m openappstack my-cluster create --ip-address IP_ADDRESS --subdomain oas example.org --create-hostname my-clusters-hostname
 ```
 
 ### DNS entries