Add Transformers metadata

This PR ensures that a "Use this model" button appears at the top right with a sample code snippet.

Would be great to add `library_name: transformers` and `pipeline_tag: text-generation` to each of the model cards :)

README.md

@@ -1,4 +1,6 @@
 ---
+library_name: transformers
+pipeline_tag: text-generation
 license: mit
 base_model:
 - ByteDance-Seed/Seed-Coder-8B-Base