update readme

examples/C++/PaddleClas/pp_shitu/README.md

 # PP-Shitu
+```
+# Dependent packages need to be installed
+pip install faiss-cpu==1.7.1.post2 -i https://mirror.baidu.com/pypi/simple
+```
 
 ## Get Model
 ```
 wget https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/rec/models/inference/serving/pp_shitu.tar.gz
-tar -xzvf pp_shitu.tar.gz
+tar -xvf pp_shitu.tar.gz
 ```
 
 ## Get test images and index
@@ -20,5 +24,5 @@ sh run_cpp_serving.sh
 
 ### Client Prediction
 ```
-python3 test_cpp_serving_pipeline.py ./drint_dataset_v1.0/test_images/nongfu_spring.jpeg
+python3 test_cpp_serving_pipeline.py ./drink_dataset_v1.0/test_images/nongfu_spring.jpeg
 ```

examples/C++/PaddleClas/pp_shitu/README_CN.md

 # PP-Shitu
+```
+# 需安装相关依赖包
+pip install faiss-cpu==1.7.1.post2 -i https://mirror.baidu.com/pypi/simple
+```
 
 ## 获取模型
 ```
 wget https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/rec/models/inference/serving/pp_shitu.tar.gz
-tar -xzvf pp_shitu.tar.gz
+tar -xvf pp_shitu.tar.gz
 ```
 
 ## 获取测试图像和index
@@ -20,5 +24,5 @@ sh run_cpp_serving.sh
 
 ### 客户端预测
 ```
-python3 test_cpp_serving_pipeline.py ./drint_dataset_v1.0/test_images/nongfu_spring.jpeg
+python3 test_cpp_serving_pipeline.py ./drink_dataset_v1.0/test_images/nongfu_spring.jpeg
 ```