update: model description (#3)

- update: model description (77ec934381620a79c8ef2a7a7d6de98f15a48c08)

README.md

@@ -13,6 +13,8 @@ library_name: transformers
 ## Model Description
 PLaMo 2 1B is a 1B model pre-trained on English and Japanese datasets, developed by Preferred Elements, Inc.
 
+PLaMo 2 models adapt the [Samba](https://arxiv.org/abs/2406.07522) architecture rather than the Transformer architecture. Samba integrates [Mamba](https://arxiv.org/abs/2312.00752), a selective State Space Model (SSM), with sliding window attention, combining their strengths for improved efficiency and performance.
+
 PLaMo 2 1B is released under Apache License version 2.0.
 
 **NOTE**: This model has **NOT** been instruction-tuned for chat dialog or other downstream tasks.