feat/idea: create an 'easter egg' in the code/project

[glaucia86]

To make the "Generative AI with JavaScript" repository more engaging and interactive, we will introduce a hidden Easter Egg that users can discover while exploring the code.

This Easter Egg will:

✅ Encourage curiosity and deeper exploration of the repository.
✅ Introduce gamification elements by rewarding users who find the secret.
✅ Enhance the learning experience in a fun way.

📌 This issue serves as the main tracking issue for the Easter Egg feature. Below are the individual sub-issues that will implement different parts of this feature.