Update README.md

Author: lixiaojun629

README.md

@@ -7,13 +7,13 @@ The UCloud Command Line Interface is a tool to manage your UCloud services. It's
 
 You can install UCloud CLI by downloading executable binary file or building from the source code by yourself.
 
-#### Download binary file:
+##### 1. Download binary file:
 [Mac](https://github.com/ucloud/ucloud-cli/releases/download/0.1.1/ucloud-cli-macosx-0.1.1-amd64.tgz) [Linux](https://github.com/ucloud/ucloud-cli/releases/download/0.1.1/ucloud-cli-linux-0.1.1-amd64.tgz)
 [Windows](https://github.com/ucloud/ucloud-cli/releases/download/0.1.1/ucloud-cli-windows-0.1.1-amd64.zip)
 
 Download the binary file and extract to /usr/local/bin directory or add it to the $PATH
 
-#### Build from source code
+##### 2. Build from source code
 
 If you have installed golang, run the following commands to install the UCloud CLI.