Add disclaimer about FromClass with classes that contain enums

[dcronqvist]

Description

Add missing disclaimer about the behaviour of nested enum properties in classes which you use FromClass on.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• Tests have been added/updated to cover new functionality.
• Documentation has been updated for all new changes (e.g., usage examples, API documentation).