docs: add onSuccess callback details to API documentation

[ggualiato]

Description

Detailing onSucess callback, when it runs and what case should be used.

• Adding new page
• [x ] Updating existing documentation
• Other updates

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[ggualiato]

Hello @shuding and @huozhi, sorry to bother, but I believe this would be a great addition to the docs because it leads developers to use the onSuccess options wrongly.

I created this PR based on my experience with a project that utilizes SWR, where the use of onSuccess was causing issues, but because it was misused and there were no more details about its behaviour in the current docs.