chore(rtos): purge all rtos documentation

Purge all outdated / invalid rtos documentation. These guys have created
some internal fork and have no plan on reintegrating with us here.

Purge associated files using:
bin/check-files.sh

Verify remaining configs using:
bin/check-configs.sh

Signed-off-by: Randolph Sapp <[email protected]>

Author: StaticRocket