Add pipeline tag and library name

This PR adds the `library_name: transformers` and `pipeline_tag: text-generation` to improve discoverability and usability of the model.

README.md

@@ -1,5 +1,7 @@
 ---
 license: afl-3.0
+library_name: transformers
+pipeline_tag: text-generation
 tags:
 - medical
 ---