[INTEGRATION] Updated README with Contributions
[INTEGRATION] Updated README with Contributions

Added informations about the Contributions folder and
the CONTRIBUTORS.txt file
cvramire/Samples,joe963852/Samples,abolger/Samples,abolger/Samples,Parrot-Developers/Samples,niavok/Samples,joe963852/Samples,pwkalana9/Samples,Parrot-Developers/Samples,pwkalana9/Samples,goldcase/myoculusbot,rolandContactor/ARDroneSDK3,rolandContactor/ARDroneSDK3,niavok/Samples,cvramire/Samples,goldcase/myoculusbot,goldcase/myoculusbot