Where to put WASI in the repo

[brettcannon]

I took a poll at https://discuss.python.org/t/should-we-have-a-platforms-directory-in-the-repo/104634/10 and it suggests creating a Platforms/ directory and moving pre-existing stuff in there. If we were to move forward with that I think it becomes a question to the SC of whether to follow through with this, and if so who should be asked to move to a new Platforms/ directory.

And if the SC doesn't want to do that, then my question becomes what alternative do you want me to go with?