minor #16267 Correct spelling & grammar in 4.4 configuration/ (gnito-org)

This PR was merged into the 4.4 branch.

Discussion
----------

Correct spelling & grammar in 4.4 configuration/

<!--

If your pull request fixes a BUG, use the oldest maintained branch that contains
the bug (see https://symfony.com/releases for the list of maintained branches).

If your pull request documents a NEW FEATURE, use the same Symfony branch where
the feature was introduced (and `5.x` for features of unreleased versions).

-->

Commits
-------

70ecc72 Correct spelling & grammar in 4.4 configuration/

Author: javiereguiluz

configuration/env_var_processors.rst

@@ -525,8 +525,8 @@ Symfony provides the following env var processors:
             $container->setParameter('private_key', '%env(default:raw_key:file:PRIVATE_KEY)%');
             $container->setParameter('raw_key', '%env(PRIVATE_KEY)%');
 
-    When the fallback parameter is omitted (e.g. ``env(default::API_KEY)``), the
-    value returned is ``null``.
+    When the fallback parameter is omitted (e.g. ``env(default::API_KEY)``), then the
+    returned value is ``null``.
 
     .. versionadded:: 4.3
 

configuration/front_controllers_and_kernel.rst

@@ -135,7 +135,7 @@ should run in "debug mode". Regardless of the
 :ref:`configuration environment <configuration-environments>`, a Symfony
 application can be run with debug mode set to ``true`` or ``false``.
 
-This affects many things in the application, such as displaying stacktraces on
+This affects many things in the application, such as displaying stack traces on
 error pages or if cache files are dynamically rebuilt on each request. Though
 not a requirement, debug mode is generally set to ``true`` for the ``dev`` and
 ``test`` environments and ``false`` for the ``prod`` environment.

configuration/multiple_kernels.rst

@@ -77,7 +77,7 @@ Now you need to define the ``ApiKernel`` class used by the new front controller.
 The easiest way to do this is by duplicating the existing  ``src/Kernel.php``
 file and make the needed changes.
 
-In this example, the ``ApiKernel`` will load less bundles than the default
+In this example, the ``ApiKernel`` will load fewer bundles than the default
 Kernel. Be sure to also change the location of the cache, logs and configuration
 files so they don't collide with the files from ``src/Kernel.php``::