Stop using deprecated interfaces

Use `Kaleidoscope.use` and `Kaleidoscope.useEventHandlerHook` instead of the
deprecated `USE_PLUGINS` and `event_handler_hook_use` interfaces.

Signed-off-by: Gergely Nagy <kaleidoscope@gergo.csillger.hu>

README.md

@@ -53,7 +53,7 @@ void systerAction(kaleidoscope::Syster::action_t action, const char *symbol) {
 void setup() {
   Serial.begin(9600);
 
-  USE_PLUGINS(&Unicode, &Syster);
+  Kaleidoscope.use(&Unicode, &Syster);
 
   Kaleidoscope.setup ();
 }

examples/Syster/Syster.ino

@@ -65,7 +65,7 @@ void systerAction(kaleidoscope::Syster::action_t action, const char *symbol) {
 }
 
 void setup() {
-  USE_PLUGINS(&Unicode, &Syster);
+  Kaleidoscope.use(&Unicode, &Syster);
 
   Kaleidoscope.setup();
 }

src/Kaleidoscope/Syster.cpp

@@ -37,7 +37,7 @@ Syster::Syster(void) {
 }
 
 void Syster::begin(void) {
-  event_handler_hook_use(eventHandlerHook);
+  Kaleidoscope.useEventHandlerHook(eventHandlerHook);
 }
 
 void Syster::reset(void) {