message: adding AMSynth to polysynth options
diff: @@ -6,6 +6,7 @@ import { isArray, isNumber } from "../core/util/TypeCheck";
  import { Instrument, InstrumentOptions } from "./Instrument";
  import { MembraneSynth, MembraneSynthOptions } from "./MembraneSynth";
  import { FMSynth, FMSynthOptions } from "./FMSynth";
  +import { AMSynth, AMSynthOptions } from "./AMSynth";
  import { MetalSynth, MetalSynthOptions } from "./MetalSynth";
  import { Monophonic } from "./Monophonic";
  import { Synth, SynthOptions } from "./Synth";
  @@ -21,6 +22,7 @@ type VoiceOptions<T> =
  T extends MembraneSynth ? MembraneSynthOptions :
  T extends MetalSynth ? MetalSynthOptions :
  T extends FMSynth ? FMSynthOptions :
  + T extends AMSynth ? AMSynthOptions :
  T extends Synth ? SynthOptions :
  never;
  