[Doc]Add qwen3_vl series guide (#3227)

### What this PR does / why we need it?
This PR provides user guide documents for Qwen3-VL 4B and
Qwen3-VL-235B-A22B.
### Does this PR introduce _any_ user-facing change?
None
### How was this patch tested?


- vLLM version: v0.10.2
- vLLM main:
https://github.com/vllm-project/vllm/commit/releases/v0.11.0

---------

Signed-off-by: booker123456 <945658361@qq.com>

docs/source/tutorials/index.md

@@ -16,6 +16,7 @@ multi_npu_quantization
 single_node_300i
 multi_node
 multi_node_kimi
+multi_node_qwen3vl
 multi_node_pd_disaggregation
 multi_node_ray
 :::