feat(config)!: Device creation function is now named entry

It now has to be called 'devices', this makes it possible to just
include the table as a whole in devices and it will automatically call
the correct function.

definitions/config.lua

@@ -14,7 +14,9 @@ local FulfillmentConfig
 ---@field schedule table<string, fun() | fun()[]>?
 local Config
 
----@alias Devices (DeviceInterface | fun(client: AsyncClient): Devices)[]
+---@alias DevicesFunction fun(mqtt_client: AsyncClient): DevicesInner
+---@alias DevicesInner (DeviceInterface | { devices: DevicesFunction } | DevicesInner)[]
+---@alias Devices DevicesFunction | DevicesInner
 
 ---@class MqttConfig
 ---@field host string