Add Robotics tag and metadata

Hi! I'm VB from Hugging Face. Congratulations on your model! I'm opening a quick PR to update the model card to add Robotics metadata.

This PR adds standard Robotics metadata to the model card:
- Added 'Robotics' to tags
- Set pipeline_tag to 'robotics'

These changes help improve discoverability of robotics-related models on the Hugging Face Hub.

README.md

@@ -47,4 +47,4 @@ python lerobot/scripts/train.py \
 --dataset.repo_id=danaaubakirova/koch_test
 ```
 
-Take a look at the [code](https://github.com/huggingface/lerobot/blob/main/lerobot/common/policies/pi0/modeling_pi0.py) regarding the implementation. 
+Take a look at the [code](https://github.com/huggingface/lerobot/blob/main/lerobot/common/policies/pi0/modeling_pi0.py) regarding the implementation.