Add getters for brightness and update_delay

Makes it easier to implement #8 as a macro.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

README.md

@@ -41,16 +41,17 @@ void setup() {
 The plugin provides two objects: `LEDRainbowEffect`, and `LEDRainbowWaveEffect`,
 both of which provide the following methods:
 
-### `.brightness(brightness)`
+### `.brightness([brightness])`
 
-> Sets the LED brightness for the effect.
+> Sets (or gets, if called without an argument) the LED brightness for the
+> effect.
 >
 > Defaults to 50.
 
-### `.update_delay(delay)`
+### `.update_delay([delay])`
 
-> Sets the number of miliseconds between effect updates. Smaller number results
+> Sets (or gets, if called without an argument) the number of milliseconds
-> in faster rainbows.
+> between effect updates. Smaller number results in faster rainbows.
 >
 > Defaults to 40.
 

src/Kaleidoscope-LEDEffect-Rainbow.h

@@ -9,7 +9,9 @@ class LEDRainbowEffect : public LEDMode {
   LEDRainbowEffect(void) {}
 
   void brightness(byte);
+  byte brightness(void) { return rainbow_value; }
   void update_delay(byte);
+  byte update_delay(void) { return rainbow_update_delay; }
   void update(void) final;
 
  private:
@@ -29,7 +31,9 @@ class LEDRainbowWaveEffect : public LEDMode {
   LEDRainbowWaveEffect(void) {}
 
   void brightness(byte);
+  byte brightness(void) { return rainbow_value; }
   void update_delay(byte);
+  byte update_delay(void) { return rainbow_update_delay; }
   void update(void) final;
 
  private: