Fix error in example code snippet

Looks like you forgot to load the image from the url in the first example. This PR fixes that.

README.md

@@ -26,6 +26,7 @@ Here is how to use this model to perform zero-shot image classification:
 
 ```python
 from transformers import pipeline
+from transformers.image_utils import load_image
 
 # load pipeline
 ckpt = "google/siglip2-base-patch16-naflex"
@@ -33,6 +34,7 @@ image_classifier = pipeline(model=ckpt, task="zero-shot-image-classification")
 
 # load image and candidate labels
 url = "http://images.cocodataset.org/val2017/000000039769.jpg"
+image = load_image(url)
 candidate_labels = ["2 cats", "a plane", "a remote"]
 
 # run inference