[Doc] Add qwen3 235b script and deepseek r1 script

[tjtanaavllm]

Purpose

Added commands to run the benchmark scenario for DeepSeek-R1-0528 and also Qwen3-235B-FP8.

Use the latest --attention-backend interface rather than VLLM_ATTENTION_BACKEND.

Test Plan

Test Result

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Essential Elements of an Effective PR Description Checklist

• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
• (Optional) The necessary documentation update, such as updating supported_models.md and examples for a new model.
• (Optional) Release notes update. If your change is user facing, please update the release notes draft in the Google Doc.