Create CODE_OF_CONDUCT.md; update contact (#1495)
Create CODE_OF_CONDUCT.md; update contact (#1495)

Co-authored-by: Wenqi Li <8ba7dfe933ef10910139377fbe2efeb7f8f88b49@nvidia.com>
Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI,Project-MONAI/MONAI