Optimize multi-node guide: more clearer corresponding relationship between configuration items and nodes ### What this PR does / why we need it? Some issues caused by misunderstandings due to unclear guidance content, for example: #3367 ### Does this PR introduce _any_ user-facing change? NA ### How was this patch tested? NA - vLLM version: v0.11.0rc3 - vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0 Signed-off-by: leo-pony <nengjunma@outlook.com>