[Doc][Model] Add Hy4-preview deployment guide (#15281)

### What this PR does / why we need it?

Hy4-privew is new model. Add Hy4-preview model deployment tutorial
covering W8A8 quantization, single-node (TP16) and dual-node (DP2 TP16)
online service deployment, functional verification, and supported
features on Ascend NPU.
- vLLM main:
https://github.com/vllm-project/vllm/commit/ba07e4a48fc951300d97eb506217dd530583dea3

Signed-off-by: voidvelocity <1225714785@qq.com>