Adds documentation for the Engine Pool feature to the `Share Level Of Kyuubi Engines` page. The separate and now-redundant `engine_pool.rst` file has been deleted.
### Why are the changes needed?
The `Share Level Of Kyuubi Engines` documentation previously lacked a section on the Engine Pool feature.
### How was this patch tested?
### Was this patch authored or co-authored using generative AI tooling?
Yes. Generative AI tools were used in several stages of preparing this contribution:
- The initial draft of the documentation was written with the assistance of Claude.
- Revisions and suggestions were provided by Gemini.
- Commit messages and pull request descriptions were refined for clarity using Gemini.
Generated-by: Claude 4, Gemini 2.5 pro
Closes#7118 from z1131392774/docs/engine-pool-feature.
Closes#7118
61892a22c [z1131392774] restore unnecessary style changes
02b4c6729 [z1131392774] ci: Re-trigger CI checks
60154e00a [z1131392774] fix with spotless
9f0700774 [z1131392774] docs: remove redundant engine_pool.md
bf586f700 [z1131392774] update with SERVER_LOCAL and Engine Pool
4d34a5bfd [z1131392774] fix format with spotless
9ed2e8a61 [z1131392774] docs(client): Add comprehensive docs for Engine Pool feature
Lead-authored-by: z1131392774 <z1131392774@gmail.com>
Co-authored-by: z1131392774 <156416015+z1131392774@users.noreply.github.com>
Signed-off-by: Cheng Pan <chengpan@apache.org>
70a2451951