This PR improves the dataset card for OST-Bench by:
- Updating the `license` to the specific `cc-by-nc-4.0` based on the GitHub repository's license information.
- Refining the `size_categories` to `10K<n<100K` to accurately reflect the dataset's 10,000 examples.
- Adding `image-text-to-text` to `task_categories` for better discoverability, complementing the existing specific VQA tasks.
- Fixing a typo in the introductory sentence ("Unstanding" to "Understanding").
- Unifying the "Code" link to `https://github.com/rbler1234/OST-Bench` for consistency with the project's GitHub README and evaluation instructions.
