[Feature]: add text-to-singing 🎤🎵

[funmolde]

Hello 😀,
I'd like to suggest adding a text-to-singing voice synthesis feature.
https://github.com/topics/singing-voice-synthesis
Thank you -_-

[abus-aikorea]

@funmolde
Your suggestion is very interesting. I will thoroughly review the repositories you have shared. I will continue to develop this project further. Thank you.