message: updating synth options
  fixes scenario where "custom" is passed in
diff: @@ -458,4 +458,4 @@ export type OmniOscillatorSynthOptions =
  OmitSourceOptions<OmniFatCustomOscillatorOptions> | OmitSourceOptions<OmniFatTypeOscillatorOptions> | OmitSourceOptions<OmniFatPartialsOscillatorOptions> |
  OmitSourceOptions<OmniFMCustomOscillatorOptions> | OmitSourceOptions<OmniFMTypeOscillatorOptions> | OmitSourceOptions<OmniFMPartialsOscillatorOptions> |
  OmitSourceOptions<OmniAMCustomOscillatorOptions> | OmitSourceOptions<OmniAMTypeOscillatorOptions> | OmitSourceOptions<OmniAMPartialsOscillatorOptions> |
  - OmitSourceOptions<ToneOscillatorConstructorOptions>;
  + OmitSourceOptions<ToneCustomOscillatorOptions> | OmitSourceOptions<ToneTypeOscillatorOptions> | OmitSourceOptions<TonePartialOscillatorOptions>
  