Update encoders.rst

Author: Simperfit

serializer/encoders.rst

@@ -25,10 +25,21 @@ Built-in Encoders
 
 The Serializer component provides built-in encoders:
 
-* :class:`Symfony\\Component\\Serializer\\Encoder\\CsvEncoder` to encode/decode CSV
-* :class:`Symfony\\Component\\Serializer\\Encoder\\JsonEncoder` to encode/decode JSON
-* :class:`Symfony\\Component\\Serializer\\Encoder\\XmlEncoder` to encode/decode XML
-* :class:`Symfony\\Component\\Serializer\\Encoder\\YamlEncoder` to encode/decode Yaml
+:class:`Symfony\\Component\\Serializer\\Encoder\\JsonEncoder`
+    This class encodes and decodes data in JSON_.
+
+:class:`Symfony\\Component\\Serializer\\Encoder\\XmlEncoder`
+    This class encodes and decodes data in XML_.
+
+:class:`Symfony\\Component\\Serializer\\Encoder\\YamlEncoder`
+    This encoder encodes and decodes data in YAML_. This encoder requires the
+    :doc:`Yaml Component </components/yaml>`.
+
+:class:`Symfony\\Component\\Serializer\\Encoder\\CsvEncoder`
+    This encoder encodes and decodes data in CSV_.
+
+All these encoders are enabled by default when using the Symfony Standard Edition
+with the serializer enabled.
 
 The ``JsonEncoder``
 ~~~~~~~~~~~~~~~~~~~