Moved the SDK-specific Contribution Instructions into the README
Moved the SDK-specific Contribution Instructions into the README

ms-iot/lightning,ms-iot/lightning,JustAddWires/galileo-sdk,ms-iot/lightning,msalehmsft/lightning,JustAddWires/galileo-sdk,msalehmsft/lightning,JustAddWires/galileo-sdk,ms-iot/lightning