updated docs

CONTRIBUTING.md

@@ -2,22 +2,37 @@
 
 ## License Agreement
 
-When providing any contributions, you must agree and be legally entitled to provide them for use and distribution in the project under the same terms as the [license](https://github.com/liabru/matter-js/blob/master/LICENSE), otherwise they can not be accepted.
+By providing any kind of contribution to this project, **you must agree and be legally entitled** to provide them for use and distribution as a part of this project **wholly under the same terms as in the original included [license](https://github.com/liabru/matter-js/blob/master/LICENSE)**.
+
+## Contributions
+
+Contributions by pull request or issues are welcome. Please ensure they follow the same style and architecture as the rest of the code. Use `npm run lint` before submitting. Please **do not include** any changes to the files in the `build` directory. 
+
+Before contributing please read the license agreement described at the beginning of this document.
 
 ## Building
 
-To build you must first install [node.js](http://nodejs.org/) and [gulp](http://gulpjs.com/), then run
+To build you must first install [node.js](http://nodejs.org), then run
 
 	npm install
 
-This will install the required build dependencies, then run
+which will install the required build dependencies, then run
 
-	gulp dev
+	npm run dev
 
-which is a task that builds the `matter-dev.js` file, spawns a development server and opens `http://localhost:8000/demo/index.html` in your browser. Any changes you make to the source will automatically rebuild `matter-dev.js` and reload your browser.
+which will run the development server and opens `http://localhost:8000/demo/index.html` in your browser. Any changes you make to the source will automatically rebuild and reload the page.
 
-## Contributions
+## Commands
 
-Contributions by pull request are welcome! Please ensure they follow the same style and architecture as the rest of the code. You should run `gulp test` and ensure there are no reported errors. Please do not include any changes to the files in the `build` directory. All contributors must agree to the license agreement described at the beginning of this document.
+The following development commands can be run at the terminal
 
-If you'd like to contribute but not sure what to work on, feel free to get in touch.
+- **npm run dev**  
+runs development server
+- **npm run build**  
+creates a release build
+- **npm run lint**  
+runs the linter
+- **npm run test**  
+runs the tests
+- **npm run doc**  
+builds the documentation