Documentation about Helm deployment in Pulsar documentation is out-dated

[lhotari]

The documentation on the Pulsar website isn't up-to-date.
https://pulsar.apache.org/docs/3.1.x/helm-deploy/

Some gaps where brought up here:
https://www.reddit.com/r/dataengineering/comments/19dry3i/comment/kjbyobe/

As an example, the section about enabling components contains info for an old version of the monitoring stack which was replaced by the kube-prometheus-stack chart. The documentation also states that you will be able to open a grafana dashboard on port 3000 after following the documentation. That was probably true before they replaced it with the kube-prometheus-stack.

[lhotari]

@Mortom123 @frankjkelly Would you like to contribute to update the Helm deployment documentation at https://pulsar.apache.org/docs/next/helm-deploy/ (maintained in repository https://github.com/apache/pulsar-site )?