Add sentence-transformers tag; will help with findability & MTEB filtering (#3)

- Add sentence-transformers tag; will help with findability & MTEB filtering (7c4a664d2f8ec321c80599a669db10b63507e5d3)


Co-authored-by: Tom Aarsen <tomaarsen@users.noreply.huggingface.co>

README.md

@@ -1,6 +1,7 @@
 ---
 library_name: transformers
 tags:
+- sentence-transformers
 - gte
 - mteb
 license: apache-2.0