fix: correct compound interest loop so interest compounds each year

[Vineshnayak]

PR Title

Fix compound interest calculation loop and output formatting

Summary

Fixed the compound interest logic so interest is applied correctly for each year. Also corrected a typo and improved output readability using round().

Description

The compound interest formula was previously placed outside the loop, causing interest to be applied only once regardless of the number of years entered. The formula has now been moved inside the loop to ensure proper yearly compounding.

Additionally:

• Corrected the typo investin to investing
• Added round() for cleaner and more readable output formatting

The changes are as follows:

• Moved compound interest calculation inside the for loop
• Fixed typo from investin to investing
• Added round() to format output values neatly

Checks

in the repository

• Made no changes that degrades the functioning of the repository
• Gave each commit a better title (unlike updated README.md)

in the PR

• Followed the format of the pull_request_template
• Made the Pull Request in a small level (for the creator's wellfare)
• Tested the changes you made

Thank You,

Vinesh nayak