Entitlement object's `starts_at` and `ends_at` is nullable, but is not documented as such

[Jiralite]

Description

According to the monetisation guide, ends_at is nullable: https://discord.com/developers/docs/monetization/implementing-app-subscriptions#how-app-subscriptions-work

starts_at is also nullable.

However, they do not appear to be documented as such:
https://discord.com/developers/docs/resources/entitlement#entitlement-object-entitlement-structure

Steps to Reproduce

N/A

Expected Behavior

Both properties documented as nullable.

Current Behavior

starts_at and ends_at are not documented as nullable.

Screenshots/Videos

No response

Client and System Information

N/A