added the sample code

README.md

@@ -2,4 +2,31 @@
 license: apache-2.0
 ---
 
-A tiny randomly-initialized [ViLT](https://arxiv.org/abs/2102.03334) used for unit tests in the Transformers VQA pipeline
+A tiny randomly-initialized [ViLT](https://arxiv.org/abs/2102.03334) used for unit tests in the Transformers VQA pipeline
+
+### How to use
+
+Here is how to use this model in PyTorch:
+
+```python
+from transformers import ViltProcessor, ViltForQuestionAnswering
+import requests
+from PIL import Image
+
+# prepare image + question
+url = "http://images.cocodataset.org/val2017/000000039769.jpg"
+image = Image.open(requests.get(url, stream=True).raw)
+text = "How many cats are there?"
+
+processor = ViltProcessor.from_pretrained("hf-internal-testing/tiny-vilt-random-vqa")
+model = ViltForQuestionAnswering.from_pretrained("hf-internal-testing/tiny-vilt-random-vqa")
+
+# prepare inputs
+encoding = processor(image, text, return_tensors="pt")
+
+# forward pass
+outputs = model(**encoding)
+logits = outputs.logits
+idx = logits.argmax(-1).item()
+print("Predicted answer:", model.config.id2label[idx])
+```