### What this PR does / why we need it?
1. Enable pymarkdown check
2. Enable python `__init__.py` check for vllm and vllm-ascend
3. Make clean code
### How was this patch tested?
- vLLM version: v0.9.2
- vLLM main:
29c6fbe58c
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Signed-off-by: wangli <wangli858794774@gmail.com>
### What this PR does / why we need it?
Add guidance on how to implement and register new models.
Modified based on PR
https://github.com/vllm-project/vllm-ascend/pull/1126, thanks for the
contribution of @linfeng-yuan.
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Signed-off-by: shen-shanshan <467638484@qq.com>