update README reference #22

Author: fabiantheblind

README.md

@@ -11,10 +11,15 @@ Extendscriptr relays on [`extendscript.prototypes`](https://github.com/fabianthe
 
 Extendscriptr doesn't use an existing full-stack polyfills like `babel-polyfill`, `es5-shim` or `shim.js` as they are intended for the browser and don't work well in adobe applications.
 
+## Prerequisites  
+
+This tool currently needs Node.js version 5.x or higher  
 
 ## Usage
-- `npm install -g extendscriptr`
-- `extendscriptr --script src/scripts/helloWorld.js --output dist/helloWord.js`
+We recommend using it as a local dependency 
+
+- `npm install extendscriptr --save-dev`
+- `./node_modules/.bin/extendscriptr --script src/scripts/helloWorld.js --output dist/helloWord.js`
 - open the outputed file with ExtendScript Toolkit OR place your script in the relevant application script folder
 - run it