Add in a couple missing var keywords to JS todo curriculum

Author: tjgrathwell

sites/en/javascript-to-do-list/adding_an_item.step

@@ -36,7 +36,7 @@ steps do
 
     source_code :javascript, <<-JAVASCRIPT
       $('#add-form').on('submit', function(event) {
-        itemDescription = event.target.itemDescription.value
+        var itemDescription = event.target.itemDescription.value
         alert('trying to create a new item with a description ' + itemDescription)
       })
     JAVASCRIPT
@@ -107,7 +107,7 @@ explanation do
   source_code :javascript, <<-JAVASCRIPT
     $('#add-form').on('submit', function(event) {
       event.preventDefault()
-      itemDescription = event.target.itemDescription.value
+      var itemDescription = event.target.itemDescription.value
       var creationRequest = $.ajax({
          type: 'POST',
          url: "https://listalous.herokuapp.com/lists/YOUR-LIST-NAME-HERE/items",

sites/en/javascript-to-do-list/marking_an_item_as_complete.step

@@ -45,7 +45,7 @@ Refresh the page and try completing an item. An alert should pop up!
 
     source_code :javascript, <<-JAVASCRIPT
       var item = $(event.target).parent()
-      isItemCompleted = item.hasClass('completed')
+      var isItemCompleted = item.hasClass('completed')
       var itemId = item.attr('data-id')
       alert('clicked item ' + itemId + ', which has completed currently set to ' + isItemCompleted)
     JAVASCRIPT
@@ -112,7 +112,7 @@ explanation do
   source_code :javascript, <<-JAVASCRIPT
     $('#list').on('click', '.complete-button', function(event) {
       var item = $(event.target).parent()
-      isItemCompleted = item.hasClass('completed')
+      var isItemCompleted = item.hasClass('completed')
       var itemId = item.attr('data-id')
 
       var updateRequest = $.ajax({