explain how to configure a non-default dbal connection

Author: dbu

bundles/phpcr_odm/introduction.rst

@@ -162,6 +162,8 @@ Once you set up Doctrine DBAL, you can configure Jackalope:
             session:
                 backend:
                     type: doctrinedbal
+                    # connection: default
+
                     # requires DoctrineCacheBundle
                     # caches:
                     #     meta: doctrine_cache.providers.phpcr_meta
@@ -193,6 +195,7 @@ Once you set up Doctrine DBAL, you can configure Jackalope:
                         logging="true"
                         profiling="true"
                     >
+                        <!-- connection="default" - option on <backend> to change dbal connection -->
                         <!--
                         <caches
                             meta="doctrine_cache.providers.phpcr_meta"
@@ -211,6 +214,7 @@ Once you set up Doctrine DBAL, you can configure Jackalope:
             'session' => array(
                 'backend' => array(
                     'type'       => 'doctrinedbal',
+                    //'connection': 'default',
                     'logging'    => true,
                     'profiling'  => true,
                     //'caches' => array(
@@ -234,7 +238,10 @@ Now make sure the database exists and initialize it:
 
 .. tip::
 
-    Of course, you can also use a different connection instead of the default.
+    You can also use a different doctrine dbal connection instead of the
+    default. Specify the dbal connection name in the ``connection`` option of
+    the ``backend`` configuration.
+
     It is recommended to use a separate connection to a separate database if
     you also use Doctrine ORM or direct DBAL access to data, rather than
     mixing this data with the tables generated by Jackalope Doctrine Dbal.  If