Add pipeline tag for better discoverability

Hi there,

Niels here from the open-source team at HF. Would be great to add the pipeline tag so that people can find the model when searching for https://huggingface.co/models?pipeline_tag=text-to-video&sort=trending.

Cheers

README.md

@@ -1,5 +1,6 @@
 ---
 license: apache-2.0
+pipeline_tag: text-to-video
 ---