Make sure user understands repercussions of using print-initial-config subcommand

> One thing left to address (not necessarily on this PR) is sensitive values. This would leak any sensitive values, so we need to make sure the user understands this

_Originally posted by @mx-psi in https://github.com/open-telemetry/opentelemetry-collector/pull/11775#pullrequestreview-2587251019_
            