refactor: harmonize method names

examples/multimatrix/main.cpp

@@ -42,7 +42,7 @@ void setup() {
     pixelController->begin();
 
     audioService = std::make_shared<MultiMatrixService>(spore.getContext(), spore.getTaskManager(), MP3PLAYER_PIN_RX, MP3PLAYER_PIN_TX, POTENTIOMETER_PIN);
-    spore.addService(audioService);
+    spore.registerService(audioService);
 
     spore.begin();