Add timeoutSignal function

[aleclarson]

It combines new AbortController() with timeout and returns the signal.

Alternatives

• Add abortIfRejected(promise) function instead, which returns an abort signal that aborts if the given promise rejects. You could do abortIfRejected(timeout(30e3)) to achieve the same thing as the proposed timeoutSignal function.
  • Pros: More flexible/reusable.
  • Cons: Clumsier API. Might be less intuitive to reach for.
  • Other possible names: promiseToSignal, toAbortSignal