Related Questions:
Automate payment dates in a Document
Is there a way to automate dates in Templates?
Show Payment Schedule in Document
How can I pull a deposit schedule into a contract?
Procedure:
Setting Payment Schedules is possible when building & sharing Invoices, but not currently on Documents. Upvote for this feature here!
You can add Booking Custom Fields using the "Date" field type for each deposit, then use those fields to pull into Documents.