coding_guide: add stuf about copy/pasting code from the next
coding_guide: add stuf about copy/pasting code from the next

Change-Id: I3ebff66a7678af433c2127f81a2e621331e80402

dmerejkowsky/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,aldebaran/qibuild,aldebaran/qibuild