[Requirement] Configuration Interface

We have two types of configuration which may or may not use the same solution for actual configuration:

1. initial configuration to provide wireless configuration
2. device configuration, e.g. device identifier, MQTT broker, probably firmware upgrades, etc.

List of possible solutions:

1. only allow configuration via some sort of UART connection that is carried along over USB
2. initial config via USB/UART onwards using a small embedded webserver
   • this is tempting, but we must also take care of the firmware image size
   • we have to find a way to get back to sleep after config (e.g. via a logout from the admin panel)
   • we have to find a way to get out of sleep if someone wants to use the admin panel
3. initial config using a small webserver and a wifi hotspot provided by the device, onwards using solution 2
   • seems to be overkill