Add an example sequence template

common/lib/xmodule/xmodule/seq_module.py

@@ -118,6 +118,8 @@ class SequenceDescriptor(MakoModuleDescriptor, XmlDescriptor):
 
     stores_state = True # For remembering where in the sequence the student is
 
+    template_dir_name = 'sequential'
+
     @classmethod
     def definition_from_xml(cls, xml_object, system):
         children = []

common/lib/xmodule/xmodule/templates/sequential/with_video.yaml

+---
+metadata:
+    display_name: Sequence with Video
+data: ''
+children:
+    - 'i4x://edx/templates/video/Empty'