Documentation about Helm deployment in Pulsar documentation is out-dated

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.

Start with the linked Pulsar 3.1.x Helm deployment documentation and compare its monitoring component instructions with the kube-prometheus-stack chart. Update the outdated component and Grafana access guidance, using the linked discussion as context; done means the documented deployment flow matches the current chart behavior.

Written by the indexing model from the issue text.