- Added `voices` parameter, which takes a list maps for each voice to add. Example:
`[ {"isLocalService": true, "isDefault": true, "voiceUri": "Ting-Ting", "name": "Ting-Ting", "lang": "zh-CN" } ... ]`
- Added `voices:blockIfNotDefined` has been added to block system voices
- Added `voices:fakeCompletion: bool` and `voices:fakeCompletion:charsPerSecond: double` to set a fake playback speed.
