Update README.md docs.

README.md

@@ -270,13 +270,11 @@ var sum int
 c := taskgroup.NewCollector(func(v int) { sum += v })
 ```
 
-Internally, a `Collector` wraps a solo task and a channel to receive results.
-
-The `Task` and `NoError` methods of the collector `c` can then be used to wrap
-a function that reports a value. If the function reports an error, that error
-is returned from the task as usual. Otherwise, its non-error value is given to
-the callback. As in the above example, calls to the function are serialized so
-that it is safe to access state without additional locking:
+The `Task`, `NoError`, and `Report`methods of the collector `c` can then be
+used to wrap a function that reports a value. If the function reports an error,
+that error is returned from the task as usual. Otherwise, its non-error value
+is given to the callback. As in the above example, calls to the function are
+serialized so that it is safe to access state without additional locking:
 
 ```go
 // Report an error, no value for the collector.
@@ -291,14 +289,21 @@ g.Go(c.Task(func() (int, error) {
 
 // Report a random integer to the collector.
 g.Go(c.NoError(func() int { return rand.Intn(1000) })
+
+// Report multiple values to the collector.
+g.Go(c.Report(func(report func(int)) error {
+   report(10)
+   report(20)
+   report(30)
+   return nil
+}))
 ```
 
-Once all the tasks are done, call `Wait` to stop the collector and wait for it
-to finish:
+Once all the tasks derived from the collector are done, it is safe to access
+the values accumulated by the callback:
 
 ```go
 g.Wait()  // wait for tasks to finish
-c.Wait()  // wait for the collector to finish
 
 // Now you can access the values accumulated by c.
 fmt.Println(sum)