update readme to add methods information

Author: chrislim2888

README.md

@@ -1,10 +1,29 @@
 # IP2Proxy PHP Module
 
-This module allows user to query an IP address if it was being used as open proxy, web proxy, VPN anonymizer and TOR exits. It lookup the proxy IP address from **IP2Location BIN Data** file. This data file can be downloaded at
+This module allows user to query an IP address if it was being used as open proxy, web proxy, VPN anonymizer and TOR exits. It lookup the proxy IP address from **IP2Proxy BIN Data** file. This data file can be downloaded at
 
 * Free IP2Proxy BIN Data: http://lite.ip2location.com
 * Commercial IP2Proxy BIN Data: http://www.ip2location.com/proxy-database
 
+## Methods
+Below are the methods supported in this class.
+
+|Method Name|Description|
+|---|---|
+|open|Open the IP2Proxy BIN data for lookup. Please see the **Usage** section of the 3 modes supported to load the BIN data file.|
+|close|Close and clean up the file pointer.|
+|getPackageVersion|Get the package version (1 to 4 for PX1 to PX4 respectively).|
+|getModuleVersion|Get the module version.|
+|getDatabaseVersion|Get the database version.|
+|isProxy|Check wether if an IP address was a proxy. Returned value:<ul><li>-1 : errors</li><li>0 : not a proxy</li><li>1 : a proxy</li><li>2 : a data center IP address</li></ul>|
+|getAll|Return the proxy information in array.|
+|getProxyType|Return the proxy type. Please visit <a href="https://www.ip2location.com/databases/px4-ip-proxytype-country-region-city-isp" target="_blank">IP2Location</a> for the list of proxy types supported|
+|getCountryShort|Return the ISO3166-1 country code (2-digits) of the proxy.|
+|getCountryLong|Return the ISO3166-1 country name of the proxy.|
+|getRegion|Return the ISO3166-2 region name of the proxy. Please visit <a href="https://www.ip2location.com/free/iso3166-2" target="_blank">ISO3166-2 Subdivision Code</a> for the information of ISO3166-2 supported|
+|getCity|Return the city name of the proxy.|
+|getISP|Return the ISP name of the proxy.|
+
 ## Usage
 
 Open and read IP2Proxy binary database. There are 3 modes: