docs: qualified that map must only take finite iterables

Author: renewooller

docs/docs/api/promise.map.md

@@ -17,7 +17,7 @@ Promise.map(
 ) -> Promise
 ```
 
-Given an [`Iterable`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols)\(arrays are `Iterable`\), or a promise of an `Iterable`, which produces promises (or a mix of promises and values), iterate over all the values in the `Iterable` into an array and [map the array to another](http://en.wikipedia.org/wiki/Map_\(higher-order_function\)) using the given `mapper` function.
+Given a finite [`Iterable`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols)\(arrays are `Iterable`\), or a promise of an `Iterable`, which produces promises (or a mix of promises and values), iterate over all the values in the `Iterable` into an array and [map the array to another](http://en.wikipedia.org/wiki/Map_\(higher-order_function\)) using the given `mapper` function.
 
 Promises returned by the `mapper` function are awaited for and the returned promise doesn't fulfill until all mapped promises have fulfilled as well. If any promise in the array is rejected, or any promise returned by the `mapper` function is rejected, the returned promise is rejected as well.