Revamp docs as UBI has evolved.

[epugh]

Description

UBI has evolved since it was first released in May 2024. This is an update of the documentation. We have introduced an explicit JS client, so we can streamline the documentation by referencing the deployed document.

Issues Resolved

Will solve https://github.com/opensearch-project/user-behavior-insights/issues/61

Version

2.18

Frontend features

n/a

Checklist

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