Our very first generation_config.json

See https://github.com/huggingface/transformers/pull/20218

generation_config.json

@@ -0,0 +1,5 @@
+{
+  "bos_token_id": 50256,
+  "eos_token_id": 50256,
+  "transformers_version": "4.25.0.dev0"
+}