Feature request: ability to reset the time counter for part/day on the schedule

[murraycadzow]

A handy feature would be the ability to reset the schedule time counter the that start of a new part/day.
Possibly expanding on this would be being able to specify a workshop start time for a part/day and the time of day be added.

Both of these would increase the ability to customise the schedule displayed for a workshop

[zkamvar]

This sounds like a good idea and I will move toward implementing it after we transition our lessons in May.

For context to anyone reading this that does not know: this was a feature that we did not port over from styles (partially because I did not know about the mechanism) in which a lesson author could place start: true in an episode YAML and that would cause the syllabus to restart the counter.

IIRC, there was also a not-very-widely-used time feature in the _config.yaml that was set to 09:00