Project Update

This update focused on improving the backend of CLi Growth and making the calculation system much more useful.

Fixed and improved the growth algorithm. The fix was much simpler than expected i basically just changed the timeframe from max to 10y.
Updated the program so users can enter an entire portfolio instead of only calculating one stock.
Added support for portfolio allocations, allowing each stock to have its own percentage of the portfolio.
Improved the overall calculation flow between main.py and computation.py.
Updated the README.md to better explain how the program works and how to use the new features.