Continued from RHIDP-2614 re: https://github.com/redhat-developer/red-hat-developers-documentation-rhdh/pull/287

Instead of giving people 20 steps to iterate though, AND having the same steps captured by QE when doing install validation tests, we should instead:

• create a script that can handle both install paths
• link to that from the docs
• reuse it in testing

Script must do the following:

• detect if oc or kubectl is installed; fail if not found and report error to user with call to action re: installing it
• detect if user is logged into a cluster and fail if not with call to action (kubectl or oc command to log in)
• if cluster router base can be detected, use that value to update the helm chart installation; if not, fail and request user pass in commandline flag as cluster router base could not be detected (can test this failure case with dev sandbox; can test passing case with clusterbot)

Script should be stored in https://github.com/redhat-developer/rhdh-chart/ using a similar documentation/script approach to

• https://github.com/janus-idp/operator/tree/main/.rhdh/docs
• https://github.com/janus-idp/operator/tree/main/.rhdh/scripts