Update model metadata to set pipeline tag to the new `text-ranking` (#1)

- Update model metadata to set pipeline tag to the new `text-ranking` (30c5dde4589ef6f13841242808750224ec3d8fe4)


Co-authored-by: Tom Aarsen <[email protected]>

README.md

@@ -2,5 +2,5 @@
 license: mit
 language:
 - en
-pipeline_tag: sentence-similarity
----
+pipeline_tag: text-ranking
+---