Use case: scheduled events

[facundoolano]

e.g. rotating schedule of deploys or demos.

1. Add a template with variables that change on every instance of the event (e.g. user in charge of a deploy)
2. allow to set instances in the calendar
3. or set recurring schedules (every thursday, every other thursday, the first thursday of every month, etc.)
4. enter the list of values to use for substitution on every instance of the event