Wrong info about amplitude range for torchaudio.load

[ailzhang]

Copied from pytorch/pytorch#19507 by @f90
Documentation for torchaudio.load says that the resulting audio is normalized to [0,1] range. However, simply loading an audio signal and looking at the output of torch.min(signal) reveals it's actually normalized to [-1,1], so the documentation should be fixed.

[calclavia]

I'm able to replicate this same issue. Is it a documentation issue or a bug in the code?

[vincentqb]

This has been fixed in #283.