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>