minor #14387 Make sure we install FrameworkExtra bundle and not just doctrine/annotations (Nyholm)

This PR was submitted for the 5.x branch but it was merged into the 4.4 branch instead.

Discussion
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Make sure we install FrameworkExtra bundle and not just doctrine/annotations

This PR will fix #14203 and revert #14198

@javiereguiluz wrote:

> There was a package called annotations-pack (see https://packagist.org/packages/symfony/annotations-pack) which allowed to run composer require annotations (when using Symfony Flex)

This is true. The pack was removed. Currently there is a flex alias to install SensioFrameworkExtraBundle when one run `composer require annotations`. That will make sure to install SensioFrameworkExtraBundle and doctrine/annotations.

One will always need SensioFrameworkExtraBundle to be able to use route config with annotations, only doctrine/annotations is not good enough.

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People that is not using Flex will see the `Could not find package annotations` as @albuquerque53 saw.

Commits
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fa569bd Make sure we install FrameworkExtra bundle and not just doctrine/annotations

Author: javiereguiluz

routing.rst

@@ -27,7 +27,7 @@ Run this command once in your application to add support for annotations:
 
 .. code-block:: terminal
 
-    $ composer require doctrine/annotations
+    $ composer require annotations
 
 In addition to installing the needed dependencies, this command creates the
 following configuration file: