- updated _sidebar
- fixed some typos in previously updated pages

FSM.md

@@ -25,7 +25,7 @@ void state_myState(const Event& ev)
 ```
 In the constructor we can specify the initial one.  
 The FSM maintains the current state by means of a pointer to one of the class methods.  
-Then, whenever a new events in received, *handleEvent()* dereferences the current state pointer, calling the relative method (and passing the event as parameter):
+Then, whenever a new event is received, *handleEvent()* dereferences the current state pointer, calling the relative method (and passing the event as parameter):
 ```cpp
 void handleEvent(const Event& e) override
 {