add publish-docker helper script

#!/bin/sh

set -e

VERSION="$1"

test -n "${VERSION}"

mosquitto_pub -h mqtt -t dmap/set/structure/0003 -m usbc_voice=1

git checkout main

git pull

git checkout "${VERSION}"

git submodule update --init

echo -n 'Waiting for ARM64 build host to become ready '

while ! test "$(docker buildx inspect mybuild | fgrep -c running)" = 2; do

	echo -n .

	sleep 5

done

echo

docker buildx build --push --no-cache --platform linux/amd64,linux/arm64 \

	--tag derfnull/efa-m:${VERSION} --tag derfnull/efa-m:latest \

	.

echo 'Turning off ARM64 build host ...'

ssh voice 'sudo poweroff'

sleep 30

mosquitto_pub -h mqtt -t dmap/set/structure/0003 -m usbc_voice=0