add notes

README.md

@@ -9,6 +9,13 @@ See this page for kernel configuration details: https://copr.fedorainfracloud.or
  - This host must be running Fedora (builds use mock)
 
 ### Example usage
+
+#### Notes
+Target Fedora version is controlled by the variable `fedora_version` in [./playbook.yml](./playbook.yml)  
+
+Patch to apply is determined by the `patch_file` variable, stored in [./payload/](./payload)
+
+#### Output:
 ```
 $ ansible-playbook -i buildserver playbook.yml -b --ask-become-pass
 BECOME password: