Events.md

+Events are widley used in *skyward-boardcore* as a form of communication among software components.  
+  
+The `src/shared/events/Event.h` file defines the **Event** struct which only contains the event ID as a member:
+```cpp
+struct Event 
+{
+    uint8_t sig;
+}
+```
+Some basic event IDs are also defined in the **EventSignal** enumeration:
+```cpp
+enum EventSignal : uint8_t
+{
+    EV_ENTRY        = 0,
+    EV_EXIT         = 1,
+    EV_EMPTY        = 2,
+    EV_INIT         = 3,
+    EV_FIRST_SIGNAL = 4
+};
+```
+
+The last one in particular, `EV_FIRST_SIGNAL` is needed when defining new custom events.  
+In fact you can defined a new enumeration that extends EventFirstSignal, in order to expand the list of event IDs. The only thing you have to keep in mind is that the first event of your new enumeration has to be set equal to `EV_FIRST_SIGNAL`. The following events in the enumeration can be manually specified or assigned automatically.  
+Moreover your enumeration should be of type `uint8_t` in order to maintain the same type of the basic event IDs.
+
+### Example
+This example shows a custom enumeration of events:
+```cpp
+enum ExampleEvents : uint8_t
+{
+    EV_1 = EV_FIRST_SIGNAL,  // first event
+    EV_2,
+    EV_3
+};
+```
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