docs/layer-contents.md: raspberrypi-cm3 is a stand alone machine now
* raspberrypi3
* raspberrypi3-64 (64 bit kernel & userspace)
* raspberrypi-cm (dummy alias for raspberrypi)
-* raspberrypi-cm3 (dummy alias for raspberrypi2)
+* raspberrypi-cm3
Note: The raspberrypi3 machines include support for Raspberry Pi 3B+.
