docs(Advanced): Add advanced developer guide

[Simpag]

Adds an advanced developer guide explaining how the Array class and Interoperability module works as well as explaining how to extend the Interoperability module with new functionality and additional frameworks.

[Copilot]

Pull request overview

This PR adds comprehensive advanced developer documentation explaining the runtime array unwrapping mechanism and interoperability system architecture in Decent Bench. It provides detailed guidance on how the Array class and interoperability module work together, how to implement new interoperability functions, and how to extend support for additional array/tensor frameworks. The documentation covers the unique TYPE_CHECKING-based optimization that eliminates wrapper object overhead while maintaining type safety, making it an essential reference for contributors extending the framework.

• Adds extensive developer guide covering the runtime unwrapping mechanism and interoperability architecture
• Provides step-by-step instructions for implementing new interoperability operations and adding framework support
• Includes code examples, best practices, and common pitfalls for working with the Array abstraction layer

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

File	Description
docs/source/index.rst	Adds the new advanced developer guide to the documentation table of contents
docs/source/developer.rst	Adds a "Next Steps" section linking to the new advanced guide
docs/source/advanced.rst	New comprehensive guide covering Array class, interoperability system architecture, runtime unwrapping, implementing new functions, adding framework support, decorator usage, and best practices

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.