Improved Fibonacci Algorithm Implementation

[Ayushmore1214]

This PR enhances the Fibonacci sequence implementation by optimizing its performance and ensuring better readability.

Changes made:

• Improved time complexity of the Fibonacci function.
• Added comments for better understanding.
• Ensured PEP8 compliance for clean code.

[algorithms-keeper]

Closing this pull request as invalid

@Ayushmore1214, this pull request is being closed as none of the checkboxes have been marked. It is important that you go through the checklist and mark the ones relevant to this pull request. Please read the Contributing guidelines.

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