[Doc] "Proxy support with SNI routing" description is confusing and conflicting

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar.

### What issue do you find in Pulsar docs?

This part is confusing:
> The proxy in Pulsar acts as a reverse proxy, and creates a gateway in front of brokers. Proxies such as Apache Traffic Server (ATS), HAProxy, Nginx, and Envoy are not supported in Pulsar. These proxy-servers support SNI routing.

In addition. the second sentence is confusing:
"The proxy server acts as a "traffic cop" in both forward and reverse proxy scenarios, and benefits your system such as load balancing, performance, security, auto-scaling, and so on."

What is "the" proxy server that the description is referring to?
As a reader, it's hard to distinguish between the Pulsar Proxy and some other proxy.

### What is your suggestion?

The whole section needs revisiting so that it would make sense. Apache Traffic Server (ATS) is a proxy server that supports SNI routing, https://docs.trafficserver.apache.org/admin-guide/layer-4-routing.en.html#sni-routing . I'm not aware that HA

### Any reference?

_No response_

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Locate the Pulsar documentation section titled "Proxy support with SNI routing" and review the sentences quoted in the issue. Clarify whether each reference means the Pulsar Proxy or an external proxy, and ensure the revised section accurately explains SNI routing and the listed proxy products.

Written by the indexing model from the issue text.