minor #15058 Fixed typo for YamlEncoder section (vertisan)

This PR was submitted for the 5.2 branch but it was merged into the 4.4 branch instead.

Discussion
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Fixed typo for YamlEncoder section

Minor typo fix for YamlEncoder section

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Commits
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e98cef4 Fixed typo for YamlEncoder section

Author: javiereguiluz

components/serializer.rst

@@ -994,7 +994,7 @@ The ``YamlEncoder`` Context Options
 The ``encode()`` method, like other encoder, uses ``context`` to set
 configuration options for the YamlEncoder an associative array::
 
-    $xmlEncoder->encode($array, 'xml', $context);
+    $yamlEncoder->encode($array, 'yaml', $context);
 
 These are the options available: