update the readme

Author: k-shlomi

README.md

@@ -200,4 +200,8 @@ You need to take the self hosted runners token from the Github Actions page of y
 #### Running on CentOS
 ```shell
 make setup-self-hosted-runner-centos token=<your-token> github_organization=<your-github-org-name>
-```
+```
+
+You will be prompted to answer some questions about your runner. \
+When you complete this step, restart your EC2 machine. \
+The runner will be automatically started on boot.