This PR enhances the dataset card for the `FreeGraspData` dataset by:
- Adding the `task_categories: robotics` field to the YAML metadata, which improves discoverability on the Hugging Face Hub. The existing `robotics` tag has been moved to this new field.
- Including the `library_name: datasets` field in the metadata to indicate compatibility with the Hugging Face `datasets` library.
- Adding a "Sample Usage" section in the content to provide users with a quick guide on how to load and inspect the dataset, along with a pointer to the main GitHub repository for more detailed examples.
