Add pipeline tag

This PR adds the pipeline tag, so that people can find your model at https://huggingface.co/models?pipeline_tag=video-text-to-text

Would be great to update the other model cards as well :)

README.md

@@ -1,5 +1,6 @@
 ---
 license: bsd-3-clause
+pipeline_tag: video-text-to-text
 ---
 
 # E.T. Chat