Update README.md

Author: ajitsing

README.md

@@ -3,3 +3,35 @@ 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.
+
+## Installation
+
+```gem install apkToJava```
+
+## Usage
+
+Below command will install the required tools for ```apkToJava``` to work
+
+```apkToJava setup```
+
+Below command will process the apk file and open the code in jadx gui
+
+```apkToJava path/to/apk/file.apk```
+
+## Supported Operatiing Systems
+- Mac
+- Linux
+
+## Todo
+Add Windows support
+
+## Want to contribute?
+Fork it ( http://github.com/ajitsing/apkToJava )
+
+Create your feature branch
+
+add feature
+
+Push to the branch
+
+Create new Pull Request