Contributing guide updated with "Good first contribution" section
Contributing guide updated with "Good first contribution" section

atilag/qiskit-sdk-py,QISKit/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,atilag/qiskit-sdk-py,QISKit/qiskit-sdk-py,atilag/qiskit-sdk-py,QISKit/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py,ChristopheVuillot/qiskit-sdk-py