update contributing guidelines

CONTRIBUTING.md

@@ -1,46 +1,46 @@
-# Contributing to RobotlegsJS
+# Contributing to RobotlegsJS-Pixi
 
 ## Setup
 
 1 - Clone your fork of the repository:
 ```
-$ git clone https://github.com/YOUR_USERNAME/RobotlegsJS.git
+$ git clone https://github.com/YOUR_USERNAME/RobotlegsJS-Pixi.git
 ```
 
-2 - Install typings:
+2 - Install npm dependencies using yarn:
 ```
-$ npm install -g typings
+$ yarn install
 ```
 
-3 - Install type definitions:
+3 - Run start process
 ```
-$ typings install
+$ yarn start
 ```
 
-4 - Install npm dependencies:
+4 - Run test process
 ```
-$ npm install
-```
-
-5 - Run build process
-```
-$ npm run build
+$ yarn test
 ```
 
 ## Guidelines
 
 - Please try to [combine multiple commits before
-pushing](http://stackoverflow.com/questions/6934752/combining-multiple-commits-before-pushing-in-git)
+pushing](http://stackoverflow.com/questions/6934752/combining-multiple-commits-before-pushing-in-git).
 
 - Please use `TDD` when fixing bugs. This means that you should write a unit
-test that fails because it reproduces the issue, then fix the issue finally run
+test that fails because it reproduces the issue, then fix the issue and finally run
 the test to ensure that the issue has been resolved. This helps us to prevent
 fixed bugs from happening again in the future.
-- Always format your code using `./node_modules/.bin/tsfmt -r`.
+
+- Always format your code using `yarn run autoformat`.
+
 - Please keep the test coverage at 100%. Write additional unit test if
-necessary
--  Please create an issue before sending a PR ff your it is going to change the
-public interface of RobotlegsJS or it includes significant architecture
+necessary.
+
+-  Please create an issue before sending a PR if your commit is going to change the
+public interface of the package or it includes significant architecture
 changes.
+
 - Feel free to ask for help from other members of the RobotlegsJS team via the
-chat or github issues.
+[gitter chat](https://gitter.im/RobotlegsJS/RobotlegsJS) or
+[github issues](https://github.com/RobotlegsJS/RobotlegsJS-Pixi/issues).