Documentazione dello script di migrazione

Hello there - as a plugin used in our Discourse instance is no longer updates (Multilingual), and some of its features are supported in the newer versions of Discourse, we wished to use a migration script in order to move values in the database to new places.

However, while researching the wiki articles from this site, or the git repository of Discourse, I haven’t found any documentation to write a migration script (what class to inherit, what methods to use…)

Is there any documentation which I missed ? Aside from looking at migration code, is there any tips to acknowledge myself around migration scripts ?

Ty in advance!