minor #12677 Removed the docs about Debug (wouterj)

This PR was merged into the 3.4 branch.

Discussion
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Removed the docs about Debug

The doc does nothing more than showing a `composer install` command and linking to a class on github.

#SymfonyHackathon

Commits
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bd47ded Removed the Debug component

Author: OskarStark

_build/redirection_map

@@ -368,3 +368,4 @@
 /introduction/from_flat_php_to_symfony2 /introduction/from_flat_php_to_symfony
 /contributing/community/other /contributing/community
 /setup/composer /setup
+/components/debug https://github.com/symfony/debug

components/class_loader.rst

@@ -34,10 +34,10 @@ Additionally, the Symfony ClassLoader component ships with a wrapper class
 which makes it possible
 :doc:`to cache the results of a class loader </components/class_loader/cache_class_loader>`.
 
-When using the :doc:`Debug component </components/debug>`, you
-can also use a special :ref:`DebugClassLoader <component-debug-class-loader>`
-that eases debugging by throwing more helpful exceptions when a class could
-not be found by a class loader.
+When using the `Debug component`_, you can also use a special
+:class:`Symfony\\Component\\Debug\\DebugClassLoader` that eases debugging by
+throwing more helpful exceptions when a class could not be found by a class
+loader.
 
 Installation
 ------------
@@ -68,6 +68,7 @@ Learn More
 
     class_loader/cache_class_loader
 
+.. _Debug component: https://github.com/symfony/debug
 .. _PSR-0: https://www.php-fig.org/psr/psr-0/
 .. _PSR-4: https://www.php-fig.org/psr/psr-4/
 .. _`autoloading mechanism`: https://php.net/manual/en/language.oop5.autoload.php

components/class_loader/debug_class_loader.rst

@@ -3,6 +3,7 @@ Debugging a Class Loader
 
 .. caution::
 
-    The ``DebugClassLoader`` from the ClassLoader component was deprecated
-    in Symfony 2.5 and removed in Symfony 3.0. Use the
-    :ref:`DebugClassLoader provided by the Debug component <component-debug-class-loader>`.
+    The ``DebugClassLoader`` from the ClassLoader component was deprecated in
+    Symfony 2.5 and removed in Symfony 3.0. Use the
+    :class:`Symfony\\Component\\Debug\\DebugClassLoader` provided by the Debug
+    component.

components/debug.rst

@@ -46,7 +46,7 @@ to `decorate`_ the kernel with additional features. Examples include:
 * Adding HTTP level caching by wrapping the kernel with an instance of
   :ref:`AppCache <symfony-gateway-cache>`;
 * Enabling (or skipping) the :doc:`ClassCache </debug/debugging>`;
-* Enabling the :doc:`Debug Component </components/debug>`.
+* Enabling the `Debug component`_.
 
 The front controller can be chosen by requesting URLs like:
 
@@ -158,6 +158,7 @@ loading the ``app/config/config_*environment*.yml`` file. You are free to
 implement this method differently if you need a more sophisticated way of
 loading your configuration.
 
+.. _Debug component: https://github.com/symfony/debug
 .. _front controller: https://en.wikipedia.org/wiki/Front_Controller_pattern
 .. _Symfony Standard Edition: https://github.com/symfony/symfony-standard
 .. _app.php: https://github.com/symfony/symfony-standard/blob/master/web/app.php