Add twig.form.resources config path

Also add Twitter Bootstrap 3 themes to it (http://symfony.com/blog/new-in-symfony-2-6-bootstrap-form-theme).

Author: bocharsky-bw

reference/configuration/twig.rst

@@ -10,13 +10,27 @@ TwigBundle Configuration ("twig")
 
         twig:
             exception_controller:  twig.controller.exception:showAction
+
             form_themes:
 
                 # Default:
                 - form_div_layout.html.twig
 
                 # Example:
                 - MyBundle::form.html.twig
+
+            form:
+                resources:
+                    # Default:
+                    - form_div_layout.html.twig
+    
+                    # Bootstrap:
+                    - bootstrap_3_layout.html.twig
+                    - bootstrap_3_horizontal_layout.html.twig
+
+                    # Example:
+                    - MyBundle::form.html.twig
+
             globals:
 
                 # Examples: