Minor reword

Author: javiereguiluz

testing.rst

@@ -22,7 +22,9 @@ wraps the original PHPUnit binary to provide additional features:
 
     $ composer require --dev symfony/phpunit-bridge
 
-After the library downloads, try executing PHPUnit by running:
+After the library downloads, try executing PHPUnit by running (the first time
+you run this, it will download PHPUnit itself and make its classes available in
+your app):
 
 .. code-block:: terminal
 
@@ -36,9 +38,6 @@ After the library downloads, try executing PHPUnit by running:
     it again. Another solution is to remove the project's ``symfony.lock`` file and
     run ``composer install`` to force the execution of all Symfony Flex recipes.
 
-The first time you run this, it will download PHPUnit itself and make its
-classes available in your app.
-
 Each test - whether it's a unit test or a functional test - is a PHP class
 that should live in the ``tests/`` directory of your application. If you follow
 this rule, then you can run all of your application's tests with the same