Spleeter: Feature request: Add demos to the README

[Joshfindit]

Some (like myself) are very curious about the methods and results, but don’t want or need to run the project ourselves.

Ideally a couple examples with starting file and resulting stems.
Maybe even at least one “ideal” example, and a least one example where the project still struggles, creating non-ideal output.

[mmoussallam]

Hi Josh,

Thanks for the suggestion, we're setting up a Google Colab. So far it has only the example file but we'll consider adding other samples with various separation performances.

[mmoussallam]

There's no easy way to add audio to the README but I guess the google colab solved this.