documentation improvements, specify added, Assert module added to unit tests by default

Author: DavertMik

src/Codeception/Module/Asserts.php

@@ -9,7 +9,8 @@
  * Class Asserts
  * @package Codeception\Module
  */
-class Asserts extends Module {
+class Asserts extends Module
+{
 
     use \Codeception\Util\Shared\Asserts {
         assertEquals as public seeEquals;