minor #9075 Fixed the link to the bin/console script (javiereguiluz)

This PR was merged into the 4.0 branch.

Discussion
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Fixed the link to the bin/console script

I recently upgraded a Symfony app to 4.0 and Flex following this guide and I noticed this link should point directly to the console script source, to ease copy+pasting it.

Commits
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4ca8082 Fixed the link to the bin/console script

Author: javiereguiluz

setup/flex.rst

@@ -254,4 +254,4 @@ manual steps:
 .. _`default services.yaml file`: https://github.com/symfony/recipes/blob/master/symfony/framework-bundle/3.3/config/services.yaml
 .. _`shown in this example`: https://github.com/symfony/skeleton/blob/8e33fe617629f283a12bbe0a6578bd6e6af417af/composer.json#L24-L33
 .. _`copying Symfony's index.php source`: https://github.com/symfony/recipes/blob/master/symfony/framework-bundle/3.3/public/index.php
-.. _`copying Symfony's bin/console source`: https://github.com/symfony/recipes/tree/master/symfony/console/3.3
+.. _`copying Symfony's bin/console source`: https://github.com/symfony/recipes/blob/master/symfony/console/3.3/bin/console