Kokoro Support

[PhilippNaused]

There is a lightweight offline TTS engine called Kokoro-82M with a .NET interface
It's easier to use and has higher quality than Windows System, cross-platform, free, and has very low latency (since it if offline).

I have been using my fork of TextToTalk (https://github.com/PhilippNaused/TextToTalk) where I added Kokoro as a new backend.

I'm very happy with the result so far.
It still needs some work, but if you're interested, I can clean it up and create a PR.

[PhilippNaused]

I will just submit the PR #247