[improve][doc] Use Text Blocks to improve JSON text

[coderzc]

Motivation

The JSON text has a lot of escape characters, we can use Text Blocks to improve it.

Modifications

Use Text Blocks to improve JSON text

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[nodece]

Could you use " instead of '?

[coderzc]

Could you use " instead of '?

OK.

[coderzc]

@nodece PTAL

[nodece]

LGTM

[coderzc]

/pulsarbot run-failure-checks

[nodece]

Overall job is optional, so you don't need to rerun the failure job.

[tisonkun]

Cool! Glad to see we gradually use new features beyond JDK11.

Out of the topic, we may be careful about using some new features like var - they will cause significant style inconsistency.

[nodece]

This is a good start, but we may need to note that this change does not benefit the cherry-pick operations, the old version doesn't support this syntax.

[coderzc]

@momo-jun PTAL

[tisonkun]

@momo-jun PTAL

I just notice this is for example shown on the doc. It can be a concern that leading whitespace may cause margin error. But fortunately Java text block detect margin by the close """ and these changes should be fine. See also https://docs.oracle.com/en/java/javase/15/text-blocks/index.html.