Add missing break statements to last example

1-js/02-first-steps/13-switch/article.md

@@ -155,6 +155,7 @@ switch (arg) {
   case '0':
   case '1':
     alert( 'One or zero' );
+    break;
 
   case '2':
     alert( 'Two' );
@@ -162,7 +163,7 @@ switch (arg) {
 
   case 3:
     alert( 'Never executes!' );
-
+    break;
   default:
     alert( 'An unknown value' )
 }