Refactor user configuration for fantasy football settings to support default values for flex percentages, multipliers, and VORP limiters. Enhanced handling of both nested and flat dictionary structures for improved flexibility in league settings.

Implement Fantasy Football VORP Calculator with user-configurable league settings and data loading from external APIs. Added functions for calculating player rankings, replacement values, and VORP metrics. Enhanced user interface for league configuration and data display.

Duplicate from streamlit/streamlit-template-space