Add library name and pipeline tag

This PR adds the missing `library_name` and `pipeline_tag` to the model card metadata. The `library_name` is set to `transformers` because the model uses the transformers library. The `pipeline_tag` is set to `text-generation` because the model generates text (Lean code).

README.md

@@ -1,14 +1,15 @@
 ---
-license: mit
-datasets:
-- kfdong/STP_Lean_SFT
 base_model:
 - deepseek-ai/DeepSeek-Prover-V1.5-SFT
+datasets:
+- kfdong/STP_Lean_SFT
+license: mit
+library_name: transformers
+pipeline_tag: text-generation
 ---
 
 This is the final Self-play Theorem Prover model as described in the paper [https://arxiv.org/abs/2502.00212](https://arxiv.org/abs/2502.00212). The training and evalution code is avaliable [here](https://github.com/kfdong/STP/tree/main).
 
-
 ```tex
 @article{dong2025beyond,
   title={Beyond Limited Data: Self-play LLM Theorem Provers with Iterative Conjecturing and Proving},