Add link to paper

This PR ensures the demo can be found at https://huggingface.co/papers/2410.05677.

Btw, would it be possible to remove the checkpoints from the Space, and instead load the checkpoints as follows:

```python
from huggingface_hub import hf_hub_download

filepath = hf_hub_download(repo_id="jiachenli-ucsb/T2V-Turbo-v2", filename="unet_mg.pt")
```

This way, the Space and model will be linked to each other.

Thanks!

Kind regards,
Niels from HF

README.md

@@ -11,4 +11,6 @@ license: apache-2.0
 short_description: Efficient T2V generation
 ---
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+
+Paper: https://huggingface.co/papers/2410.05677