Create generation_config.json

fix: Entry Not Found for url: https://huggingface.co/openchat/openchat_3.5/resolve/main/generation_config.json.
of many projects require generation_config.json
when using
```
model.generation_config = GenerationConfig.from_pretrained("openchat/openchat_3.5")
````

generation_config.json

@@ -0,0 +1,6 @@
+{
+  "_from_model_config": true,
+  "bos_token_id": 1,
+  "eos_token_id": 32000,
+  "transformers_version": "4.34.1"
+}