Adding MIOpen Contributing Guide (#932)
Adding MIOpen Contributing Guide (#932)

Co-authored-by: Jun Liu <51861ea3e40e2b6bedfd8e0dda66e2c7a35a25e3@amd.com>
Co-authored-by: Artem Tamazov <1c9ed91d484328fc0bb5e06d7ac41a6a9e16a73b@gmail.com>
ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen,ROCmSoftwarePlatform/MIOpen