doc: Release notes for v2.0 - initial (empty) draft
doc: Release notes for v2.0 - initial (empty) draft

Get things started for Zephyr 2.0 release notes.
Individual teams will update their appropriate sections.

Signed-off-by: Ioannis Glaropoulos <5921cc8bab7e1d4329f52fd8f6268f9692e3de80@nordicsemi.no>

Vudentz/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,nashif/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,finikorg/zephyr