update readme

README.md

@@ -44,6 +44,15 @@ This model slightly differs from the previous SFT model [`rinna/japanese-gpt-neo
 
     The data will **not** be released.
 
+* **Model Series**
+
+    | Variant | Link |
+    | :-- | :--|
+    | 3.6B PPO | https://huggingface.co/rinna/japanese-gpt-neox-3.6b-instruction-ppo |
+    | 3.6B SFT-v2 | https://huggingface.co/rinna/japanese-gpt-neox-3.6b-instruction-sft-v2 |
+    | 3.6B SFT | https://huggingface.co/rinna/japanese-gpt-neox-3.6b-instruction-sft |
+    | 3.6B pretrained | https://huggingface.co/rinna/japanese-gpt-neox-3.6b |
+    
 * **Authors**
     
     [Tianyu Zhao](https://huggingface.co/tianyuz) and [Kei Sawada](https://huggingface.co/keisawada)