Clarify use of buffered channel in the timeouts example.

The buffered channel prevents goroutine leaks in case the
channel doesn't end up being read (as indeed happens to c1).

Updates #207

examples/timeouts/timeouts.go

@@ -12,7 +12,10 @@ func main() {
 
 	// For our example, suppose we're executing an external
 	// call that returns its result on a channel `c1`
-	// after 2s.
+	// after 2s. Note that the channel is buffered, so the
+	// send in the goroutine is nonblocking. This is a
+	// common pattern to prevent goroutine leaks in case the
+	// channel is never read.
 	c1 := make(chan string, 1)
 	go func() {
 		time.Sleep(2 * time.Second)

examples/timeouts/timeouts.hash

@@ -1,2 +1,2 @@
-93343e1aacb14f818c87732914c29ba57afab245
-MgcfA-xpJO9
+b1e8d0efbabd0c52271a85fad5ad58dcd1c7c476
+gyY_qDsRVUe