doc: Release notes initial (empty) draft
doc: Release notes initial (empty) draft

Get things started for the 1.4 release notes.
Individual teams will update their appropriate sections.

Signed-off-by: David B. Kinder <c56c8b29908a5b2af1b63001268d73a0b7f972ba@intel.com>

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