Correct license in metadata

The license was changed on the original HF repo, likely because the model was partially based on the Alpaca dataset, which prohibits commercial use.

README.md

@@ -1,6 +1,6 @@
 ---
 inference: false
-license: mit
+license: cc-by-nc-sa-4.0
 language:
 - en
 library_name: transformers