docs: add missing header text for VQA model

README.md

@@ -43,7 +43,7 @@ model = Pix2StructForConditionalGeneration.from_pretrained('google/matcha-chart2
 url = "https://raw.githubusercontent.com/vis-nlp/ChartQA/main/ChartQA%20Dataset/val/png/20294671002019.png"
 image = Image.open(requests.get(url, stream=True).raw)
 
-inputs = processor(images=image, return_tensors="pt")
+inputs = processor(images=image, text="Generate underlying data table of the figure below:", return_tensors="pt")
 predictions = model.generate(**inputs, max_new_tokens=512)
 print(processor.decode(predictions[0], skip_special_tokens=True))
 ```