deprecate iterable, asyncIterable

Their only purpose seems to be converting an object like:

{
  next: ()  => {}
}

to an iterable. I don’t think they are particularly useful, given that if you already manage to have that, you can probably add:

{
  next: ()  => {},
  [Symbol.iterator]: function () {
    return this
  }
}

Also the name doesn’t really tell you what they do.

[conartist6]

I certainly hope that the methods aren’t/wouldn’t be used much, but it also seems like a pretty elementary operation. The core design of iterables creates two separate concepts. Iterators and iterables are a fundamental part of the system, not just a mistake that will be papered over eventually. Given that anyone who understands how these concepts work together should understand what this function does, I don’t think we should probably keep it. We could however clean up the documentation, and more actively direct people to just make their iterators iterables instead using these methods.

[sithmel]

Removed them. I added some extra documentation about iterables and iterators