[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_node.md

@@ -108,7 +108,6 @@ export TP_SOCKET_IFNAME=$nic_name
 export HCCL_SOCKET_IFNAME=$nic_name
 export OMP_PROC_BIND=false
 export OMP_NUM_THREADS=100
-export VLLM_USE_V1=1
 export HCCL_BUFFSIZE=1024
 
 # The w8a8 weight can obtained from https://www.modelscope.cn/models/vllm-ascend/DeepSeek-V3-W8A8