Tweak wording and remove trailing whitespace

examples/stateful-goroutines/stateful-goroutines.go

@@ -46,14 +46,14 @@ func main() {
     writes := make(chan *writeOp)
 
     // Here is the goroutine that owns the `state`, which
-    // is a map as in the previous example, but is held 
+    // is a map as in the previous example but now private
-    // internally so all changes are handled by this function.
+    // to the stateful goroutine. This goroutine repeatedly
-    // This goroutine repeatedly selects on the `reads` and
+    // selects on the `reads` and `writes` channels,
-    // `writes` channels, responding to requests as they
+    // responding to requests as they arrive. A response
-    // arrive. A response is executed by first performing
+    // is executed by first performing the requested
-    // the requested operation and then sending a value
+    // operation and then sending a value on the response
-    // on the response channel `resp` to indicate success
+    // channel `resp` to indicate success (and the desired
-    // (and the desired value in the case of `reads`).
+    // value in the case of `reads`).
     go func() {
         var state = make(map[int]int)