Merge pull request #578 from unao/master

Fixing small issues in docs.

Author: mattpodwysocki

doc/api/core/operators/flatmaplatest.md

@@ -27,7 +27,7 @@ var source = Rx.Observable
 
 var subscription = source.subscribe(
   function (x) {
-    console.log('Next: %', x);
+    console.log('Next: %s', x);
   },
   function (err) {
     console.log('Error: %s', err);

doc/api/core/operators/merge.md

@@ -21,7 +21,8 @@ var source2 = Rx.Observable.interval(150)
 
 var source = Rx.Observable.merge(
     source1,
-    source2);
+    source2)
+    .take(5);
 
 var subscription = source.subscribe(
     function (x) {