Changed duration() to currentDuration() and added examples

src/Bounce2.cpp

@@ -104,7 +104,7 @@ unsigned long Debouncer::previousDuration() const {
 	return durationOfPreviousState;
 }
 
-unsigned long Debouncer::duration() const {
+unsigned long Debouncer::currentDuration() const {
 	return (millis() - stateChangeLastTime);
 }
 

src/Bounce2.h

@@ -137,7 +137,8 @@ public:
       @return The duration in milliseconds (unsigned long) of the current state.
      */
 
-  unsigned long duration() const;
+  unsigned long currentDuration() const;
+
 
   /**
      @brief Returns the duration in milliseconds of the previous state.