[Doc] Add qwen3 embedding 8b guide (#1734)

1. Add the tutorials for qwen3-embedding-8b
2. Remove VLLM_USE_V1=1  in docs, it's useless any more from 0.9.2


- vLLM version: v0.9.2
- vLLM main:
5923ab9524

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

docs/source/tutorials/multi_npu_quantization.md

@@ -1,6 +1,6 @@
 # Multi-NPU (QwQ 32B W8A8)
 
-## Run docker container:
+## Run docker container
 :::{note}
 w8a8 quantization feature is supported by v0.8.4rc2 or higher
 :::