Add pipeline tag and library name

This PR adds the `pipeline_tag` and `library_name` to the model card metadata for better discoverability and clarity. The `pipeline_tag` is set to `text-generation` as Ling is a large language model. The `library_name` is set to `transformers` because the provided usage example utilizes the Hugging Face `transformers` library.

README.md

@@ -1,5 +1,7 @@
 ---
 license: mit
+library_name: transformers
+pipeline_tag: text-generation
 ---
 
 # Ling