Add MockAPI-PHP to the [API] section

[ka215]

This PR adds MockAPI-PHP to the [API] section.

MockAPI-PHP is a lightweight, file-based mock API server built with PHP 8.3+.
It allows developers to simulate RESTful APIs using .json or .txt response files — no backend or framework required.

Key features:

• Dynamic endpoints and polling
• Error simulation and response delays
• Simple CLI or browser interface
• Automatic OpenAPI 3.0 schema generation from response data

GitHub: https://github.com/ka215/MockAPI-PHP