Added CLI usage instructions.

Author: ip2location

README.md

@@ -9,19 +9,50 @@ You can access to the commercial databases from https://www.ip2location.com/prox
 For more details, please visit:
 [http://www.ip2location.com/ip2proxy/developers/c](http://www.ip2location.com/ip2proxy/developers/c)
 
+
+
 ## Developer Documentation
+
 To learn more about installation, usage, and code examples, please visit the developer documentation at [https://ip2proxy-c.readthedocs.io/en/latest/index.html.](https://ip2proxy-c.readthedocs.io/en/latest/index.html)
 
+
+
 ## Testing
 
     cd test
     ./test-IP2Proxy
 
+
+
 ## Sample BIN Databases
 
 * Download free IP2Proxy LITE databases at [https://lite.ip2location.com](https://lite.ip2location.com)  
 * Download IP2Proxy sample databases at [https://www.ip2location.com/ip2proxy/developers](https://www.ip2location.com/ip2proxy/developers)
 
+
+
+## IP2Proxy CLI
+
+Query an IP address and display the result
+
+```
+ip2proxy -d [IP2PROXY BIN DATA PATH] --ip [IP ADDRESS]
+```
+
+Query all IP addresses from an input file and display the result
+
+```
+ip2proxy -d [IP2PROXY BIN DATA PATH] -i [INPUT FILE PATH]
+```
+
+Query all IP addresses from an input file and display the result in XML format
+
+```
+ip2proxy -d [IP2PROXY BIN DATA PATH] -i [INPUT FILE PATH] --format XML
+```
+
+
+
 ## Support
 
 Email: [email protected].