Its a bit rough with SherpaOnnx and eSpeak - So PR's welcome.
Idea here is this is a unifed TTS wrapper so getVoices is the same for all engines, and bytestream is the same and word events are the same - even if they don't support it we estimate it.
Maybe useful since I see a lot of TTS hackers out there!
NB: I will say JS isnt my bag - so feedback all welcome.
