Add pipeline tag

This PR adds the appropriate pipeline tag, ensuring the model can be found at https://huggingface.co/models?pipeline_tag=image-to-image&sort=trending

README.md

@@ -1,3 +1,7 @@
+---
+pipeline_tag: image-to-image
+---
+
 # **Scaling Image Tokenizers with Grouped Spherical Quantization**
 ---