[dev-5][Layout] Update migration guide

[MarvinKlein1508]

Pull Request

📖 Description

This PR fixes the migration guide for FluentLayout. During development LayoutArea.Menu has been replaced with LayoutArea.Navigation

🎫 Issues

Closes #4854

📑 Test Plan

✅ Checklist

General

• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

Component-specific

• I have added a new component
• I have added Unit Tests for my new component
• I have modified an existing component
• I have validated the Unit Tests for an existing component

⏭ Next Steps

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Updates the FluentLayout migration guide to reflect the rename of LayoutArea.Menu to LayoutArea.Navigation.

Changes:

• Replaces LayoutArea.Menu with LayoutArea.Navigation in the migration snippet
• Updates the displayed label from “Menu” to “Navigation”