Add Exercism Cairo track to Tutorials and Examples section

[Giri-Aayush]

We should add the Exercism Cairo track to our Tutorials and Examples section. Exercism is a well-known platform for learning programming languages through hands-on exercises and mentorship.

Proposed addition:

• Exercism Cairo Track - Learn and master Cairo through hands-on exercises with community-powered mentorship.
  

This addition will provide users with another valuable resource for learning Cairo, offering a structured, interactive approach to mastering the language.