doc: Enhance subsection on "Stable API Change" label
doc: Enhance subsection on "Stable API Change" label

Remove part that it is not appropriate.

Signed-off-by: Aleksandar Markovic <8084fc9c6866c5a3f7ad74f44ee247322c1b4f7a@gmail.com>

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