doc(CONTRIBUTING): upgraded the contribution documentation
doc(CONTRIBUTING): upgraded the contribution documentation

laurentpetit/ccw,ccw-ide/ccw,noncom/ccw,ccw-ide/ccw,noncom/ccw,michelangelo13/ccw,michelangelo13/ccw,ccw-ide/ccw,laurentpetit/ccw,michelangelo13/ccw,laurentpetit/ccw,noncom/ccw