update docs of performance test (#4352)

* update performance test

* update docs of performance test

docs/document/content/features/test-engine/performance-test.cn.md

@@ -346,9 +346,7 @@ DELETE FROM tbl1 WHERE id=?
 
 #### 压测类
 
-```shell
-参考https://github.com/apache/incubator-shardingsphere-benchmark/tree/master/shardingsphere-benchmark
-```
+参考[shardingsphere-benchmark](https://github.com/apache/incubator-shardingsphere-benchmark/tree/master/shardingsphere-benchmark)实现，注意阅读其中的注释
 
 #### 编译
 

docs/document/content/features/test-engine/performance-test.en.md

@@ -351,9 +351,8 @@ DELETE FROM tbl1 WHERE id=?
 
 #### Jmeter Class
 
-```shell
-See: https://github.com/apache/incubator-shardingsphere-benchmark/tree/master/shardingsphere-benchmark
-```
+Consider the implementation of [shardingsphere-benchmark](https://github.com/apache/incubator-shardingsphere-benchmark/tree/master/shardingsphere-benchmark)
+Notes: the notes in incubator-shardingsphere-benchmark/README.md should be taken attention to
 
 #### Compile & Build