Update demo vllm script and docs

demo/demo_vllm.py

@@ -11,6 +11,7 @@ parser = argparse.ArgumentParser()
 parser.add_argument("--ip", type=str, default="localhost")
 parser.add_argument("--port", type=str, default="8000")
 parser.add_argument("--model_name", type=str, default="rednote-hilab/dots.ocr")
+parser.add_argument("--image_path", type=str, default="demo/demo_image1.jpg")
 parser.add_argument("--prompt_mode", type=str, default="prompt_layout_all_en",help=(
         "Choose a task prompt: "
         "prompt_layout_all_en=full document layout+OCR to JSON/MD; "
@@ -28,7 +29,7 @@ require_version("openai>=1.5.0", "To fix: pip install openai>=1.5.0")
 
 def main():
     addr = f"http://{args.ip}:{args.port}/v1"
-    image_path = "demo/demo_image1.jpg"
+    image_path = args.image_path
     prompt = dict_promptmode_to_prompt[args.prompt_mode]
     image = Image.open(image_path)
     response = inference_with_vllm(