Update 'README.md'

README.md

@@ -1,3 +1,15 @@
 # expose
 
-ngrok php实现
+ngrok php实现
+
+## Usage
+
+安装
+```
+docker run expose share http://192.168.2.100 # share a local site
+docker run expose serve my-domain.com # start a server
+
+expose share http://localhost:3000
+
+```
+