Add connect 4 game link

[rimsha-shoukat]

Add Connect Four game project link

Description

Added a Connect Four game project link to the README, built using HTML, CSS & JavaScript.

Motivation and Context

Connect Four is a great beginner-to-intermediate level project. It covers core JavaScript concepts like DOM manipulation, 2D arrays, game logic, and CSS Grid layout — making it a solid addition to the project-based learning list for anyone looking for a fun, visual challenge.

How Has This Been Tested?

Opened the live demo link and confirmed the project loads correctly.

Types of changes

• Content Update (change which fixes an issue or updates an already existing submission)
• New Article (change which adds functionality)
• Documentation change

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have made checks to ensure URLs and other resources are valid