Added "grainSize" parameter to the initializer comments. (#44)

* Add a user-definable "grain size" to PhaseLockedVocoder

The size of the mincer in the DSP can be set on init of PhaseLockedVocoder in a range of 128...8192. A smaller value makes the sound crisper when the sample position is moved. But a greater mincer size might also be desirable because the spectral freeze changes audibly.

* Formatting

* Added grain size param to the comments

* Line length

Author: maweibezahn

Sources/SoundpipeAudioKit/Generators/PhaseLockedVocoder.swift

@@ -65,6 +65,7 @@ public class PhaseLockedVocoder: Node {
     ///   - position: Position in time. When non-changing it will do a spectral freeze of a the current point in time.
     ///   - amplitude: Amplitude.
     ///   - pitchRatio: Pitch ratio. A value of. 1  normal, 2 is double speed, 0.5 is halfspeed, etc.
+    ///   - grainSize: Size (samples, pow 2) of the spectral freeze. Lower sizes – crisper sound when moving position.
     ///
     public init(
         file: AVAudioFile,