Merge pull request #2 from ApsaraDB/yz/readme_fix

Update readme for tool reference.

Author: koperjian

Readme-CN.md

@@ -75,7 +75,7 @@ sudo /usr/local/polarstore/pfsd/bin/clean_pfsd.sh nvme1n1
 
 ##### 5. 使用PFS工具进行检查。
 
-   参照[PFS工具使用说明](PFS_Tools-CN.md)，进行常见的文件操作，验证文件系统是否正确安装。
+   参照[PFS工具使用说明](docs/PFS_Tools-CN.md)，进行常见的文件操作，验证文件系统是否正确安装。
    例如使用如下命令，可以查看创建的新文件 hello.txt：
 
 ```bash

Readme.md

@@ -74,7 +74,9 @@ sudo /usr/local/polarstore/pfsd/bin/clean_pfsd.sh nvme1n1
 
 ##### 5. Use the PFS tool to check whether PFS is running as expected. 
 
-   Perform common operations on files to verify that PFS is running as expected. For more information, see Instruction to the [PFS tool](PFS_Tools-EN.md). 
+   Perform common operations on files to verify that PFS is running as
+    expected. For more information, see Instruction to the [PFS tool
+    ](docs/PFS_Tools-EN.md). 
    For example, you can run the following commands to view the new file hello.txt:
 
 ```