docs(select): Updated ngOptions track by examples

src/ng/directive/select.js

@@ -42,9 +42,9 @@ var ngOptionsMinErr = minErr('ngOptions');
  * or property name (for object data sources) of the value within the collection. If a `track by` expression
  * is used, the result of that expression will be set as the value of the `option` and `select` elements.
  *
- * ### `select as` with `trackexpr`
+ * ### `select as` with `track by`
  *
- * Using `select as` together with `trackexpr` is not recommended. Reasoning:
+ * Using `select as` together with `track by` is not recommended. Reasoning:
  *
  * - Example: <select ng-options="item.subItem as item.label for item in values track by item.id" ng-model="selected">
  *   values: [{id: 1, label: 'aLabel', subItem: {name: 'aSubItem'}}, {id: 2, label: 'bLabel', subItem: {name: 'bSubItem'}}],
@@ -70,7 +70,9 @@ var ngOptionsMinErr = minErr('ngOptions');
  *     * `label` **`for`** `value` **`in`** `array`
  *     * `select` **`as`** `label` **`for`** `value` **`in`** `array`
  *     * `label`  **`group by`** `group` **`for`** `value` **`in`** `array`
- *     * `select` **`as`** `label` **`group by`** `group` **`for`** `value` **`in`** `array` **`track by`** `trackexpr`
+ *     * `label` **`group by`** `group` **`for`** `value` **`in`** `array` **`track by`** `trackexpr`
+ *     * `label` **`for`** `value` **`in`** `array` | orderBy:`orderexpr` **`track by`** `trackexpr` 
+ *        (for including a filter with `track by`)
  *   * for object data sources:
  *     * `label` **`for (`**`key` **`,`** `value`**`) in`** `object`
  *     * `select` **`as`** `label` **`for (`**`key` **`,`** `value`**`) in`** `object`