Improve model card: Add pipeline tag and library name

This PR enhances the model card for `SenseLLM/StructureCoder-7B` by:

- Adding the `pipeline_tag: text-generation`, which makes the model discoverable under the text-generation pipeline on the Hugging Face Hub (https://huggingface.co/models?pipeline_tag=text-generation).
- Adding the `library_name: transformers`, enabling an automated code snippet to be displayed for easy usage with the `transformers` library, as evidenced by the `config.json` (Qwen2ForCausalLM architecture and transformers version).

These changes improve the model's visibility and usability for the community.

README.md

@@ -1,8 +1,11 @@
 ---
-license: apache-2.0
 language:
 - en
+license: apache-2.0
+pipeline_tag: text-generation
+library_name: transformers
 ---
+
 ## Alignment with Fill-In-the-Middle for Enhancing Code Generation
 
 <p align="center">