Add pipeline tag and library name to model card

This PR adds the `pipeline_tag` to the model card metadata, specifying the model's functionality as `image-to-video`.
It also adds the `library_name`.
This will improve discoverability on the Hugging Face Hub.

README.md

@@ -1,6 +1,9 @@
 ---
 license: apache-2.0
+library_name: diffusers
+pipeline_tag: image-to-video
 ---
+
 <meta name="google-site-verification" content="-XQC-POJtlDPD3i2KSOxbFkSBde_Uq9obAIh_4mxTkM" />
 
 <div align="center">