Add StickHero game project to Game Development section

[Namitjain07]

Description

This PR adds my StickHero game project to the Game Development section of the Project-Based-Learning repository.

StickHero is a simple and fun Java/JavaFX arcade-style game where the player grows a stick to cross from one platform to another. The project includes well-structured code using design patterns (Singleton, Flyweight), clean UI, sound effects, gameplay animations, and a full README with screenshots and a demo video.

Motivation and Context

This addition expands the Game Development section with a complete beginner-friendly Java game project that others can clone, learn from, and build upon.
It demonstrates JavaFX UI design, animations, event handling, and object-oriented patterns.
It also includes a demo video, screenshots, and step-by-step instructions.

Project Link:
https://github.com/Namitjain07/STICKHERO

How Has This Been Tested?

• The project builds and runs successfully using JavaFX.
• Tested gameplay interactions, platform generation, stick placement, and sound effects on Windows.
• All resources (images, sounds, controller logic) load correctly.

Types of changes

• New Article (change which adds functionality)

Checklist:

• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have ensured my URL is working and publicly accessible.
• The added entry follows the list formatting conventions.