Remove dashboard config info and point to official doc instead.

[erwangranger]

This Jira is now complete, so we should review the content (in https://access.redhat.com/documentation/en-us/red_hat_openshift_ai_self-managed/2-latest/html/managing_resources/customizing-the-dashboard#doc-wrapper ) and

1. remove the duplicate information
2. point to the documentation.