Update README.md

Nested double quote strings are not allowed for Python versions before 3.12.

README.md

@@ -81,7 +81,7 @@ def add_row(content, data, i, with_answer=False):
     content.append({ "type": "text",
             "text": "Image " + str(i) + ": " + data["question"] + "\n" + mcq })
     content.append({ "type": "image_url",
-            "image_url": {"url": f"data:image/jpeg;base64,{encode_image(data["image"])}",
+            "image_url": {"url": f"data:image/jpeg;base64,{encode_image(data['image'])}",
                 "detail": "low"}})
     if with_answer:
         content.append({"type": "text", "text": "Answer {}: ".format(i) + correct_option_letter})