Pitch shifting

[waterplea]

Hello @qiuxiang! Thank you for this library. I'm using it for pitch detection in my browser karaoke game and it works great. I thought of adding transposition so I can lower particularly high pitched songs into player's vocal range. I know there's a pitchshift effect in aubio, but it's not present i this wrapper. I have no experience in WASM so I don't think I will be able to add it myself. Is there any plans on updating this repo with more features from aubio?

[qiuxiang]

I'm interested in adding this feature even though I never used pitchshift in aubio. But im a bit busy recently, so not sure when it can be implemented.