go-tour: use ctrl-enter to fmt, not shift-space

Apparently I type shift-space a lot when I type,
so this new shortcut key gets in my way.
I suppose I'm not the only one.

LGTM=campoy
R=campoy, golang-codereviews
CC=golang-codereviews
https://codereview.appspot.com/117250045

content/welcome.article

@@ -34,7 +34,7 @@ These example programs demonstrate different aspects of Go. The programs in the
 
 Edit the program and run it again.
 
-Note that when you click on [[javascript:highlightAndClick("#format")][Format]] or `shift-space`
+Note that when you click on [[javascript:highlightAndClick("#format")][Format]] or `ctrl-enter`
 the text in the editor is formatted using the
 [[http://golang.org/cmd/gofmt/][gofmt]] tool. You can switch on and off syntax highlighting
 the clicking on [[javascript:highlightAndClick(".syntax-checkbox")][syntax]] button.

static/js/values.js

@@ -61,15 +61,15 @@ value('ui.config', {
             'Shift-Enter': function() {
                 $('#run').click();
             },
+            'Ctrl-Enter': function() {
+                $('#format').click();
+            },
             'PageDown': function() {
                 return false;
             },
             'PageUp': function() {
                 return false;
             },
-            'Shift-Space': function() {
-                $('#format').click();
-            },
         }
     }
-});
+});