Add badges for version.

docs/README.md

 ## Documents
+[![version](https://img.shields.io/badge/document--version-3.2.5--2017-green.svg)]() 
 [![cn doc](https://img.shields.io/badge/document-中文-blue.svg)](README_ZH.md)
 
   * Getting Started
@@ -24,4 +25,3 @@
     * [Skywalking 3 Cross Process Propagation Headers Protocol, v1.0](en/Skywalking-3-Cross-Process-Propagation-Headers-Protocol.md)
   * FAQ
 
-    
\ No newline at end of file

docs/README_ZH.md

 ## 中文文档
+[![version](https://img.shields.io/badge/document--version-3.2.5--2017-green.svg)]() 
 [![EN doc](https://img.shields.io/badge/document-English-blue.svg)](README.md)
 
   * [项目简介](/README_ZH.md)
@@ -29,4 +30,4 @@
     * [探针与Collector间网络协议，v3.2+](cn/How-to-communicate-with-the-collector-CN.md)
   * FAQ
     * [Trace查询有数据，但是没有拓扑图和JVM数据?](cn/FAQ/Why-have-traces-no-others-CN.md)
-    * [加载探针，Console被GRPC日志刷屏](cn/FAQ/Too-many-gRPC-logs-CN.md)
\ No newline at end of file
+    * [加载探针，Console被GRPC日志刷屏](cn/FAQ/Too-many-gRPC-logs-CN.md)