update docs (#536)

Signed-off-by: hsliu <liuhongsheng4@huawei.com>

docs/getting_started/installation/gpu/cuda.inc.md

@@ -42,8 +42,10 @@ If you do not need to modify source code of vLLM, you can directly install the s
 uv pip install vllm==0.12.0 --torch-backend=auto
 ```
 
+The release 0.12.0 of vLLM is based on PyTorch 2.9.0 which requires CUDA 12.9 environment.
+
 #### Installation of vLLM-Omni
-Install additional requirements for vLLM-Omni
+Since vllm-omni is rapidly evolving, it's recommended to install it from source
 ```bash
 git clone https://github.com/vllm-project/vllm-omni.git
 cd vllm-omni