Add pipeline tag to metadata

This PR adds the `pipeline_tag: image-classification` to the metadata of the model card to improve its discoverability on the Hugging Face Hub. It also fixes the syntax highlighting for the usage code snippet by changing the block language from `bash` to `python`.

README.md

@@ -1,5 +1,6 @@
 ---
 license: apache-2.0
+pipeline_tag: image-classification
 tags:
 - Face
 - Face Recognition
@@ -55,7 +56,7 @@ FaceMoE replaces the standard transformer FFN with multiple expert MLPs and a le
 
 You can download the weights using:
 
-```bash
+```python
 from huggingface_hub import hf_hub_download
 
 # Finetuned Weights