release-notes: Fill release highlights
release-notes: Fill release highlights

kYc0o/RIOT,jasonatran/RIOT,kYc0o/RIOT,ant9000/RIOT,RIOT-OS/RIOT,ant9000/RIOT,ant9000/RIOT,kYc0o/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,ant9000/RIOT,kaspar030/RIOT,kaspar030/RIOT,jasonatran/RIOT,miri64/RIOT,kaspar030/RIOT,miri64/RIOT,miri64/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,miri64/RIOT,kYc0o/RIOT,kaspar030/RIOT,kYc0o/RIOT,miri64/RIOT,ant9000/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,kaspar030/RIOT