co2_sensor: Show firmware version at startup

ampel-firmware/co2_sensor.cpp

@@ -69,8 +69,9 @@ namespace sensor {
      *  SDA --- SDA (GPIO21) //NOTE: GPIO1 would be more convenient (right next to GPO3)
      */
 #endif
+    Serial.println();
+    scd30.enableDebugging(); // Prints firmware version in the console.
 
-    // CO2
     if (!scd30.begin(config::auto_calibrate_sensor)) {
       Serial.println(F("ERROR - CO2 sensor not detected. Please check wiring!"));
       led_effects::showKITTWheel(color::red, 30);
@@ -81,7 +82,6 @@ namespace sensor {
 
     // SCD30 has its own timer.
     //NOTE: The timer seems to be inaccurate, though, possibly depending on voltage. Should it be offset?
-    Serial.println();
     Serial.print(F("Setting SCD30 timestep to "));
     Serial.print(config::measurement_timestep);
     Serial.println(" s.");