doc/user.rst: add more links

doc/plugins.rst

@@ -690,6 +690,8 @@ Valid quality values for libsoxr:
 * "low"
 * "quick"
 
+.. _output_plugins:
+
 Output plugins
 --------------
 

doc/user.rst

@@ -365,10 +365,14 @@ More information can be found in the :ref:`decoder_plugins` reference.
 Configuring encoder plugins
 ---------------------------
 
-Encoders are used by some of the output plugins (such as shout). The encoder settings are included in the audio_output section.
+Encoders are used by some of the output plugins (such as shout). The
+encoder settings are included in the ``audio_output`` section, see :ref:`config_audio_output`.
 
 More information can be found in the :ref:`encoder_plugins` reference.
 
+
+.. _config_audio_output:
+
 Configuring audio outputs
 -------------------------
 
@@ -422,6 +426,8 @@ The following table lists the audio_output options valid for all plugins:
        (:samp:`none`). By default, the hardware mixer is used for
        devices which support it, and none for the others.
 
+More information can be found in the :ref:`output_plugins` reference.
+
 Configuring filters
 -------------------