Feedback: MOLT Fetch - needs to discuss migrating tables together that have FK relationships

Page: https://cockroachlabs.com/docs/molt/molt-fetch.html

## What is the reason for your feedback?

[X] Missing the information I need

[ ] Too complicated

[ ] Out of date

[ ] Something is broken

[ ] Other

## Additional details

The page discusses how to select subsets of the tables to migrate. It also says:

> If a table in the source database is much larger than the other tables, [filter and export the largest table](https://www.cockroachlabs.com/docs/molt/molt-fetch#schema-and-table-selection) in its own molt fetch task. Repeat this for each of the largest tables. Then export the remaining tables in another task.

In neither of these discussions does it mention that tables with FK relationships between them should be migrated together.

Jira issue: DOC-13944