Add Apache 2.0 license, link to paper

This PR adds the license (`apache-2.0`) to the model card, so that people are aware of the license under which the model is released. It also adds a direct link
to the paper page on Hugging Face.

README.md

@@ -11,7 +11,9 @@ language:
 base_model:
 - Efficient-Large-Model/Sana_1600M_1024px
 pipeline_tag: text-to-image
+license: apache-2.0
 ---
+
 <p align="center" style="border-radius: 10px">
   <img src="https://raw.githubusercontent.com/NVlabs/Sana/refs/heads/main/asset/logo.png" width="35%" alt="logo"/>
 </p>
@@ -21,7 +23,7 @@ pipeline_tag: text-to-image
   <a href="https://github.com/NVlabs/Sana"><img src="https://img.shields.io/static/v1?label=Code&message=Github&color=blue&logo=github"></a> &ensp;
   <a href="https://nvlabs.github.io/Sana/"><img src="https://img.shields.io/static/v1?label=Project&message=Github&color=blue&logo=github-pages"></a> &ensp;
   <a href="https://hanlab.mit.edu/projects/sana/"><img src="https://img.shields.io/static/v1?label=Page&message=MIT&color=darkred&logo=github-pages"></a> &ensp;
-  <a href="https://arxiv.org/abs/2410.10629"><img src="https://img.shields.io/static/v1?label=Arxiv&message=Sana&color=red&logo=arxiv"></a> &ensp;
+  <a href="https://huggingface.co/papers/2410.10629"><img src="https://img.shields.io/static/v1?label=Arxiv&message=Sana&color=red&logo=arxiv"></a> &ensp;
   <a href="https://nv-sana.mit.edu/"><img src="https://img.shields.io/static/v1?label=Demo&message=MIT&color=yellow"></a> &ensp;
   <a href="https://discord.gg/rde6eaE5Ta"><img src="https://img.shields.io/static/v1?label=Discuss&message=Discord&color=purple&logo=discord"></a> &ensp;
 </div>
@@ -52,7 +54,7 @@ Source code is available at https://github.com/NVlabs/Sana.
 - **Model Description:** This is a model that can be used to generate and modify images based on text prompts. 
 It is a Linear Diffusion Transformer that uses one fixed, pretrained text encoders ([Gemma2-2B-IT](https://huggingface.co/google/gemma-2-2b-it))
 and one 32x spatial-compressed latent feature encoder ([DC-AE](https://hanlab.mit.edu/projects/dc-ae)).
-- **Resources for more information:** Check out our [GitHub Repository](https://github.com/NVlabs/Sana) and the [Sana report on arXiv](https://arxiv.org/abs/2410.10629).
+- **Resources for more information:** Check out our [GitHub Repository](https://github.com/NVlabs/Sana) and the [Sana report on arXiv](https://huggingface.co/papers/2410.10629).
 
 ### Model Sources