[Notifier] Add Update slack message article

Author: maxim-dovydenok-busuu

notifier/chatters.rst

@@ -223,6 +223,38 @@ The result will be something like:
 .. image:: /_images/notifier/slack/message-reply.png
    :align: center
 
+.. versionadded:: 5.3
+
+    The ``threadTs()`` method was introduced in Symfony 5.3.
+
+Updating a Slack Message
+----------------------------------
+
+Save full message id when sending a message::
+
+    use Symfony\Component\Notifier\Bridge\Slack\SlackSentMessage;
+    use Symfony\Component\Notifier\Message\ChatMessage;
+
+    $sentMessage = $chatter->send(new ChatMessage('Original message'));
+
+    // Make sure that Slack transport was used
+    if ($sentMessage instanceOf SlackSentMessage) {
+        $fullMessageId = $sentMessage->getFullMessageId();
+    }
+
+Use full message id to create
+:class:`UpdateMessageSlackOptions` class::
+
+    use Symfony\Component\Notifier\Bridge\Slack\UpdateMessageSlackOptions;
+    use Symfony\Component\Notifier\Message\ChatMessage;
+
+    $options = new UpdateMessageSlackOptions($fullMessageId);
+    $chatter->send(new ChatMessage('Updated message', $options));
+
+.. versionadded:: 6.2
+
+    The ``UpdateMessageSlackOptions`` class was introduced in Symfony 6.2.
+
 Adding Interactions to a Discord Message
 ----------------------------------------