Add model card with metadata for CB-LLM

This PR adds a model card with the appropriate metadata including `pipeline_tag`, `library_name`, and `license`. It also includes links to the paper, the GitHub repository and the project page.

README.md

@@ -0,0 +1,35 @@
+---
+pipeline_tag: text-generation
+library_name: transformers
+license: apache-2.0
+tags:
+  - interpretable
+  - text-classification
+  - text-generation
+---
+
+# Concept Bottleneck Large Language Models
+
+This repository contains the Concept Bottleneck Large Language Model (CB-LLM) presented in [Concept Bottleneck Large Language Models](https://huggingface.co/papers/2412.07992).
+
+[Project Website](https://lilywenglab.github.io/CB-LLMs/)
+
+Code: [https://github.com/Trustworthy-ML-Lab/CB-LLMs](https://github.com/Trustworthy-ML-Lab/CB-LLMs)
+
+This model offers inherent interpretability and controllability in text generation. See the linked paper and GitHub repository for details on training and usage.
+
+## Usage (Example - Text Generation)
+
+```python
+from transformers import pipeline, AutoTokenizer
+
+model_name = "cesun/cbllm-generation" #replace with actual model name
+pipe = pipeline(
+    "text-generation",
+    model_name,
+    tokenizer=AutoTokenizer.from_pretrained(model_name, trust_remote_code=True),
+    device_map="auto",
+    trust_remote_code=True,
+)
+print(pipe("The key to life is", max_new_tokens=20, do_sample=True)[0]["generated_text"])
+```