Add model card

This PR adds a model card for the model described in [CLEAR: Conv-Like Linearization Revs Pre-Trained Diffusion Transformers Up](https://huggingface.co/papers/2412.16112).

It also adds a link to the Github repository, and it adds the appropriate `pipeline_tag`.

README.md

@@ -1,3 +1,7 @@
----
-license: apache-2.0
----
+---
+library_name: diffusers
+pipeline_tag: image-to-image
+---
+This repository contains the model of the paper [CLEAR: Conv-Like Linearization Revs Pre-Trained Diffusion Transformers Up](https://huggingface.co/papers/2412.16112).
+
+Code: https://github.com/Huage001/CLEAR