Standups: enhanced recurrence settings to specify when the standup will close

[jordanh]

Issue - Enhancement

SpaceCAMP reported to us that they are using our Async Standup feature for what it was designed for! During a feedback call, they passed the feedback to us that they wished when they set up the standup recurrence that the date for the standup would reflect when the standup is intended to close, not when it was opened.

SpaceCAMP are create their standups 24 hours before they are intended to close.

Opening as a design task in order to explore how we might add this configuration open

Acceptance Criteria (optional)

Designed explored and shared where users can:

• Specify the date they would like to use for the recurrence (opening or closing date)

Estimated effort: 5 points (see CONTRIBUTING.md)