Improve model card: add license, pipeline tag and library name

This PR improves the model card by adding the following metadata:

- `license: apache-2.0`
- `library_name: transformers`
- `pipeline_tag: text-generation`

This enables the "how to use" button on the top right, and makes the model discoverable at https://huggingface.co/models?pipeline_tag=text-generation&sort=trending.

README.md

@@ -3,7 +3,11 @@ datasets:
 - EleutherAI/pile
 language:
 - en
+license: apache-2.0
+library_name: transformers
+pipeline_tag: text-generation
 ---
+
 # Model Card
 
 This model is pretrained Based model. 
@@ -40,4 +44,4 @@ Please consider citing this paper if you use our work:
 }
 ```
 
-Please reach out to simarora@stanford.edu, eyuboglu@stanford.edu, and mzhang20@stanford.edu with questions.
+Please reach out to simarora@stanford.edu, eyuboglu@stanford.edu, and mzhang20@stanford.edu with questions.