[FEATURE] Add NAM to conda-forge

[sdatkinson]

What

Add this package to conda-forge so that conda install -c conda-forge neural-amp-modeler works.

How

https://conda-forge.org/docs/maintainer/adding_pkgs/

Why

I need to remember why I wanted this. I believe that the reason was that PyTorch doesn't install well from pip when the user is on Linux or Windows and has an nVIDIA GPU (not sure about ROCm). However, I'd like to pinpoint what isn't working to convince myself that this is the right way to go. PyPI is a more commonly-used index, so if I can make it "just work" with that, then that might be even better because (1) better support for the more common use case, and (2) less to maintain from my perspective.