feature #4140 [Cookbook][Logging] document multiple recipients in XML configs (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[Cookbook][Logging] document multiple recipients in XML configs

| Q             | A
| ------------- | ---
| Doc fix?      | no
| New docs?     | yes (symfony/monolog-bundle#91)
| Applies to    | all
| Fixed tickets | #3940, #4135

Commits
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37ab23d document multiple recipients in XML configs

Author: weaverryan

cookbook/logging/monolog_email.rst

@@ -58,10 +58,18 @@ it is broken down.
                     name="swift"
                     type="swift_mailer"
                     from-email="error@example.com"
-                    to-email="error@example.com"
                     subject="An Error Occurred!"
-                    level="debug"
-                />
+                    level="debug">
+
+                    <monolog:to-email>error@example.com</monolog:to-email>
+
+                    <!-- or multiple to-email elements -->
+                    <!--
+                    <monolog:to-email>dev1@example.com</monolog:to-email>
+                    <monolog:to-email>dev2@example.com</monolog:to-email>
+                    ...
+                    -->
+                </monolog:handler>
             </monolog:config>
         </container>