added help link to azure iot hub node
added help link to azure iot hub node

thingsboard/thingsboard,thingsboard/thingsboard,volodymyr-babak/thingsboard,volodymyr-babak/thingsboard,thingsboard/thingsboard,thingsboard/thingsboard,volodymyr-babak/thingsboard,volodymyr-babak/thingsboard,thingsboard/thingsboard,thingsboard/thingsboard,volodymyr-babak/thingsboard,volodymyr-babak/thingsboard