[Doc] add persistent batch inference GIF (#43)

* [Doc] add persistent batch inference

* update

* update

* Update README.md

* Update README_zh-CN.md

README.md

@@ -62,7 +62,7 @@ LMDeploy is a toolkit for compressing, deploying, and serving LLM, developed by
 
 - Support persistent-batch inference
 
-  TODO: gif to show what persistent batch is
+![PersistentBatchInference](https://github.com/open-mmlab/lmdeploy/assets/25839884/8f8b57b8-42af-4b71-ad74-e75f39b10694)
 
 ## Quick Start
 

README_zh-CN.md

@@ -62,7 +62,7 @@ LMDeploy 是 [MMRazor](https://github.com/open-mmlab/mmrazor) 和 [MMDeploy](htt
 
 - 支持 persistent batch 推理方式
 
-  TODO: gif to show what persistent batch is
+![PersistentBatchInference](https://github.com/open-mmlab/lmdeploy/assets/25839884/8f8b57b8-42af-4b71-ad74-e75f39b10694)
 
 ## 快速上手