Add DevContainers Support for PhlexUI Project

[cirdes]

Description

I would like to propose the addition of DevContainers support to the PhlexUI project. DevContainers, a feature of Visual Studio Code and GitHub Codespaces, provides a consistent and reproducible development environment, making it easier for contributors to get started with the project.

Benefits

• Consistent Development Environment: Ensures that all contributors have a consistent development setup, reducing the "it works on my machine" issues.
• Quick Onboarding: New contributors can quickly start developing without having to manually set up their local environment.
• Preconfigured Tools and Dependencies: Automatically includes all necessary tools and dependencies, ensuring that the development environment is correctly configured.