Add initial version of CODE_OF_CONDUCT.md
Add initial version of CODE_OF_CONDUCT.md

Signed-off-by: Andrei Gherzan <0401b4310c02ae595fc6a2b84ead073cab9b0442@huawei.com>

agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi