Add visualisation

[alexespencer]

No description provided.

[Copilot]

Pull Request Overview

This PR adds a visualisation module to the project, integrating a nannou-based application that renders points along with a quadtree structure and interactive UI elements. Key changes include:

• Implementation of a new Model in Rust to manage points and quadtree operations.
• Addition of a nannou app with event handling for mouse inputs to add and query points.
• Updates to Cargo.toml and README.md to support the new visualisation functionality.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
visualize/src/model.rs	New module for managing the quadtree, points and rendering logic.
visualize/src/main.rs	Main app setup with event handling and drawing routines.
visualize/src/lib.rs	Module export for the visualisation components.
visualize/Cargo.toml	Dependency updates and workspace configuration for new libraries.
quadtree/src/lib.rs	Minor export update for quadtree functionality.
README.md	Documentation update with instructions and an app demo.