Please update README.md concerning config mismatch and what to expect from different Rave model architecture/configs/channels

[ballerburg9005]

The config files mentioned in the README.md mismatch the recent config files provided by msprior. It is unclear what to pick now.

When do you get a "semantic control" interface, and when not?

What Rave architecture/configs/channel counts work with msprior, and what penalties/drawbacks are there if choosing this and that?

How long to train until usable/optimal results?

I have already raised an issue in Rave for various questions, that also pertain to msprior.

https://github.com/acids-ircam/RAVE/issues/299