update readme

Signed-off-by: binliu <binliu@nvidia.com>

README.md

@@ -24,7 +24,6 @@ with tempfile.TemporaryDirectory() as tmp_dir:
     pipeline_helper = HuggingFacePipelineHelper("vista3d")
     pipeline = pipeline_helper.init_pipeline(
         os.path.join(FILE_PATH, "vista3d_pretrained_model"),
-        output_dir=output_dir,
         device=torch.device("cuda:0"),
     )
     inputs = [
@@ -37,7 +36,7 @@ with tempfile.TemporaryDirectory() as tmp_dir:
             "label_prompt": [3],
         },
     ]
-    pipeline(inputs)
+    pipeline(inputs, output_dir=output_dir)
 
 ```
 The inputs defines the image to segment and the prompt for segmentation.