[TASK][MEDIUM] Document for Kyuubi UI usage

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

### Search before creating

- [X] I have searched in the [task list](https://github.com/orgs/apache/projects/296) and found no similar tasks.

### Mentor

- [X] I have sufficient knowledge and experience of this task, and I volunteer to be the mentor of this task to guide contributors to complete the task.

### Skill requirements

- English writing skills
- Markdown or reStructureText

### Background and Goals

This issue aims to provide user guides to describe what is kyuubi web UI and how to use it.

### Implementation steps

https://kyuubi.readthedocs.io/en/master/client/ui/index.html

Write user-friendly usage guides for kyuubi web UI page by page

### Additional context

_No response_

Start with the Kyuubi Web UI page linked in the issue and review the existing page structure. Document the UI page by page in user-friendly Markdown or reStructuredText guides; the work is done when users can understand what the UI is and how to use each page.

Written by the indexing model from the issue text.