Fixing help strings for shift|ctrl+enter.

IPython/html/static/notebook/js/keyboardmanager.js

@@ -88,7 +88,7 var IPython = (function (IPython) {
             }
         },
         'shift+enter' : {
-            help    : 'run cell',
+            help    : 'run cell, select below',
             help_index : 'ba',
             handler : function (event) {
                 IPython.notebook.execute_cell_and_select_below();
@@ -96,7 +96,7 var IPython = (function (IPython) {
             }
         },
         'ctrl+enter' : {
-            help    : 'run cell, select below',
+            help    : 'run cell',
             help_index : 'bb',
             handler : function (event) {
                 IPython.notebook.execute_cell();