feat: user definable callback on state transition

src/statemachine.cpp

@@ -71,6 +71,9 @@ namespace sta
 				HeapStats_t stats;
 				vPortGetHeapStats(&stats);
 
+				// Execute the user-defined callback.
+				sta::tacos::onStateTransition(transition.from, transition.to, transition.lockout);
+
 				// Start all new tasks and stop all the tasks that aren't supposed to be running.
 				updateThreads();
 			}