Merge branch '5.4' into 6.0

* 5.4:
  [Notifier] Fix typo OneSignal DSN
  Fix blank space typo
  [Form] Add missing imports in unmapped fields example

Author: javiereguiluz

configuration.rst

@@ -57,7 +57,7 @@ Configuration Formats
 ~~~~~~~~~~~~~~~~~~~~~
 
 Unlike other frameworks, Symfony doesn't impose a specific format on you to
-configure your applications, but lets you choose between YAML, XML and PHP. 
+configure your applications, but lets you choose between YAML, XML and PHP.
 Throughout the Symfony documentation, all configuration examples will be
 shown in these three formats.
 

forms.rst

@@ -939,6 +939,8 @@ example to add an *"I agree with these terms"* checkbox), set the ``mapped``
 option to ``false`` in those fields::
 
     // ...
+    use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
+    use Symfony\Component\Form\Extension\Core\Type\SubmitType;
     use Symfony\Component\Form\FormBuilderInterface;
 
     class TaskType extends AbstractType

notifier.rst

@@ -34,7 +34,7 @@ The notifier component supports the following channels:
   services like Slack and Telegram;
 * :ref:`Email channel <notifier-email-channel>` integrates the :doc:`Symfony Mailer </mailer>`;
 * Browser channel uses :ref:`flash messages <flash-messages>`.
-* Push Channel sends notifications to phones and browsers via push notifications.
+* :ref:`Push channel <notifier-push-channel>` sends notifications to phones and browsers via push notifications.
 
 .. tip::
 
@@ -294,6 +294,8 @@ notification emails:
             ;
         };
 
+.. _notifier-push-channel:
+
 Push Channel
 ~~~~~~~~~~~~
 
@@ -312,7 +314,7 @@ integration with these push services:
 Service         Package                               DSN
 ==============  ====================================  =================================================================================
 Expo            ``symfony/expo-notifier``              ``expo://Token@default``
-OneSignal       ``symfony/one-signal-notifier``        ``onesignal://APP_ID:API_KEY@default?defaultRecipientId=DEFAULT_RECIPIENT_ID''``
+OneSignal       ``symfony/one-signal-notifier``        ``onesignal://APP_ID:API_KEY@default?defaultRecipientId=DEFAULT_RECIPIENT_ID``
 ==============  ====================================  =================================================================================
 
 To enable a texter, add the correct DSN in your ``.env`` file and