(doc): update llm-scaler/vllm/README.md, adding subsection 1.6,1.7,1.8; modifying subsection 1.4 (#30)

* (doc): update llm-scaler/vllm/README.md, adding subsection 1.6,1.7,1.8

* (doc): update llm-scaler/vllm/README.md

* (doc) Update /llm-scaler/vllm/README.md

* (doc): update llm-scaler/vllm/README.md

* (doc): update llm-scaler/vllm/README.md

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Co-authored-by: Chen <nan1.chen@intel.com>

Author: Arcs-ur