Add README for deleting instance profile .

[jayunit100]

When re-creating, you need to do this:

 aws iam delete-instance-profile --instance-profile-name openshift-instance-profile

Because I think the instance-profiles otherwise cause a terraform error.

Maybe add it to the shell script or something?

Note: otherwise this is a hard error to fix, bc instance-profiles dont show up in the AWS console :)

[jayunit100]

Done ; closing. Thanks for the quick review @dwmkerr!