Example migrations in 'migration/' directory do not work

Problem/Motivation

After enabling the example module I was not able to run the migrations in '/migration'. This is a typo as the directory should be '/migrations' but after fixing it, I am getting

You must declare "ids" as a unique array of fields in your source settings.

Steps to reproduce

Proposed resolution

Determine if these migrations are useful. If not, delete, if so, update to work and possible keep the group uniformed with the other migrations.

Remaining tasks

User interface changes

API changes

Data model changes