Break 'calendar' video (13) into smaller segments

[brylie]

The calendar video is nearly 20 minutes in length, and may omit crucial steps. If you break the video into smaller chunks it might make managing and refactoring the videos easier, like software decomposition.

E.g. sections would be

• Create the calendar templates
• Create calendar model/schema
• Define calendar methods
• Create calendar modal

I.e. if a tutorial is running longer than, say, 5 minutes, it may be good to segment it.