Add dataset card with task category and links

This PR adds the `video-text-to-text` task category to the dataset card YAML, links the dataset to its paper, project page, and code repository, and includes a short dataset description with a download snippet taken from the GitHub README.

README.md

@@ -1,3 +1,27 @@
 ---
 license: apache-2.0
+task_categories:
+- video-text-to-text
 ---
+
+# AskStream
+
+AskStream is the first multi-turn benchmark spanning video and user uncertainty for streaming video understanding. It extends proactive video interaction with an **ASK** action, allowing models to proactively request missing information before answering, in addition to the conventional **WAIT** and **ANSWER** actions.
+
+The benchmark contains **438** videos across **9** diverse domains, **1,401** questions covering **8** subtasks, and **2,714** manually annotated frame-level time windows for three interaction types: **WAIT**, **ASK**, and **ANSWER**. It supports both multiple-choice and open-ended evaluation across four task categories.
+
+- **Paper:** [AskStream: When and What to Ask Proactively under Uncertainty in Streaming Video Understanding](https://huggingface.co/papers/2610.38678)
+- **Project page:** [https://askstream.top/](https://askstream.top/)
+- **Code:** [https://github.com/wanglu-cs/AskStream](https://github.com/wanglu-cs/AskStream)
+
+## Sample usage
+
+The repository README provides the following command to download the dataset:
+
+```bash
+python -m pip install -U huggingface_hub
+
+hf download wanglucs/AskStream \
+  --repo-type dataset \
+  --local-dir /mnt/userdata/AskStream/data
+```