docs: Clarify product team review role.
This MR clarifies the role of product in the discovery process, and makes it clear that its involvement is not merely for adding a single line item concerning the design phase, but is also critical to the format and scope of the document.
JIRA tickets: https://tasks.opencraft.com/browse/STAR-3859
Discussions: https://forum.opencraft.com/t/updates-to-discovery-instructions/1879/11
Merge deadline: "None" if there's no rush, "ASAP" if it's critical, or provide a specific date if there is one.
Testing instructions:
- Check the built version of the documentation to make sure the formatting is sensible.