v2.6.0

New features:

1. support for nested maps and lists in state section, with converters added on any level.
2. support for list of registers with converter in availability section.
3. improved performance for configurations with a lot of modbus networks and many MQTT command and state topics:
   • added relation map for poll group to MQTT state topics.
   • added relation map for MQTT command topics to register data.
4. Added multi device support for poll groups and mqtt topics