[Doc] Add the missing configuration override information

[momo-jun]

Search before asking

• I searched in the issues and found nothing similar.

What issue do you find in Pulsar docs?

Background
The reference doc for configurations has been moved to the new page https://pulsar.apache.org/reference/, and the content will be auto-generated from the code. See here for more explanations.

Issue
The following content for configuration override in the original topic (related PR #15818) is missing and needs to be manually maintained.

• for clients internal to brokers
• for clients internal to websocket
• for clients internal to proxy

What is your suggestion?

Add the missing information back to a proper place, either the existing config page or the new config page.

Any reference?

No response

cc @michaeljmarshall @Anonymitaet

Are you willing to submit a PR?

• I'm willing to submit a PR!