Add related projects and differences in regard to this one to the readme

Just popping into this issue to say I have a feature branch with a drush command (migrate_default_content:export-migrations [mdcem]) that allows you to export the generated migrations.

It also provides a new setting on the settings form to control where those migrations get exported to.

Once I get a little more testing done and possibly add some options for only exporting specific migrations then it'll be merged into the 3.x branch.

All new drush commands are being written for Drush 12 with (currently) no plan to backport them to older versions, so to get this feature you'll need to be on Drupal 10.2.x with Drush 12.