Improve model card: Add reinforcement learning tag, library name, and link to code

This PR improves the model card by adding the `reinforcement-learning` pipeline tag and linking to the project page and GitHub repository. A basic description of the model is also added to improve discoverability.

README.md

@@ -1,3 +1,27 @@
----
-license: apache-2.0
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+---
+license: apache-2.0
+pipeline_tag: reinforcement-learning
+library_name: transformers
+---
+
+# ARMAP: Scaling Autonomous Agents via Automatic Reward Modeling And Planning
+
+[Project Page](https://armap-agent.github.io) | [Paper](https://arxiv.org/abs/2502.12130) | [Model Weights](https://huggingface.co/Heaplax/ARMAP-RM-LoRA)
+
+This repository contains the reward model for the paper [Scaling Autonomous Agents via Automatic Reward Modeling And Planning](https://arxiv.org/abs/2502.12130). This reward model automatically learns a reward function from environment interactions.
+
+Code: https://github.com/armap-agent/ARMAP
+
+## Citation
+If you use this work or find it helpful, please consider citing:
+```
+@misc{chen2025scalingautonomousagentsautomatic,
+      title={Scaling Autonomous Agents via Automatic Reward Modeling And Planning}, 
+      author={Zhenfang Chen and Delin Chen and Rui Sun and Wenjun Liu and Chuang Gan},
+      year={2025},
+      eprint={2502.12130},
+      archivePrefix={arXiv},
+      primaryClass={cs.AI},
+      url={https://arxiv.org/abs/2502.12130}, 
+}
+```