[skip ci] Update README remove CN pages

Signed-off-by: NJinHai-CN <hai.jin@zilliz.com>

README.md

@@ -10,8 +10,6 @@
 [![CodeFactor Grade](https://www.codefactor.io/repository/github/milvus-io/milvus/badge)](https://www.codefactor.io/repository/github/milvus-io/milvus)
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/c4bb2ccfb51b47f99e43bfd1705edd95)](https://app.codacy.com/gh/milvus-io/milvus?utm_source=github.com&utm_medium=referral&utm_content=milvus-io/milvus&utm_campaign=Badge_Grade_Dashboard)
 
-English | [中文版](README_CN.md) 
-
 ## What is Milvus
 
 As an open source vector similarity search engine, Milvus is easy-to-use, highly reliable, scalable, robust, and blazing fast. Adopted by over 100 organizations and institutions worldwide, Milvus empowers applications in a variety of fields, including image processing, computer vision, natural language processing, voice recognition, recommender systems, drug discovery, etc. 

docs/README.md

@@ -18,8 +18,3 @@ The following is a list of existing test reports:
 - [IVF_SQ8H](test_report/milvus_ivfsq8h_test_report_detailed_version.md)
 - [IVFLAT](test_report/ivfflat_test_report_en.md)
 
-To read the CN version of these reports:
-
-- [IVF_SQ8_cn](test_report/milvus_ivfsq8_test_report_detailed_version_cn.md)
-- [IVF_SQ8H_cn](test_report/milvus_ivfsq8h_test_report_detailed_version_cn.md)
-- [IVFLAT_cn](test_report/ivfflat_test_report_cn.md)