Issue Description

The current data-core documentation explains how to use selectors like getEntityRecords and getEntityRecord, but it does not document how entities themselves are defined and configured.

Section of Page with the issue

Every selectors for Entities, starting from geteditedentityrecord

Why is this a problem?

At the moment, developers need to read the source code to discover the meaning of these fields.

Suggested Fix

Add a dedicated section to the data-core documentation that explains:

• The entity configuration object structure.
• The purpose of each field with examples.