Add pipeline tag and move license to metadata

This PR adds the relevant pipeline tag to the model card metadata, enabling people to find your model at https://huggingface.co/models?pipeline_tag=audio-to-video. It also moves the license to the metadata section.

README.md

@@ -1,3 +1,8 @@
+---
+license: afl-3.0
+pipeline_tag: audio-to-video
+---
+
 This is the official checkpoints of "Sonic: Shifting Focus to Global Audio Perception in Portrait Animation".
 
 Project Page: https://jixiaozhong.github.io/Sonic/
@@ -6,8 +11,4 @@ Paper: https://arxiv.org/pdf/2411.16331
 
 Code: https://github.com/jixiaozhong/Sonic
 
-Welcome to try.
-
----
-license: afl-3.0
----
+Welcome to try.