[1/2/N] Enable pymarkdown and python __init__ for lint system (#2011)

### 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

---------

Signed-off-by: wangli <wangli858794774@gmail.com>

docs/source/user_guide/support_matrix/supported_models.md

@@ -34,7 +34,6 @@ Get the newest info here: https://github.com/vllm-project/vllm-ascend/issues/160
 | XLM-RoBERTa-based | ✅ |  |
 | Molmo | ✅ |  |
 
-
 ## Multimodal Language Models
 
 ### Generative Models