Update README.md

Author: ajitsing

README.md

@@ -6,6 +6,9 @@ A ruby gem to view android apk as java code in GUI
 Before starting the process it checks wether the env is setup or not.
 If not it downloads the required tools and continues with the process.
 
+## Documentation
+http://www.singhajit.com/convert-apk-file-to-java-code/
+
 ## Installation
 
 ```gem install apkToJava```