refactor: Improve logic and redability.

[NitkarshChourasia]

This pull request introduces comprehensive foundational documentation for the Nifty 50 Stock Analyzer project. It adds both a requirements specification and a detailed design document, establishing clear functional expectations and a robust technical blueprint for the CLI tool. The documentation covers user stories, acceptance criteria, architecture, data models, error handling, and testing strategies, providing a strong basis for implementation and future development.

Requirements Specification:

• Added .kiro/specs/nifty-stock-analyzer/requirements.md, detailing user stories and acceptance criteria for all major features, including data fetching, moving average calculation, momentum detection, CSV export, user feedback, and robust error handling.

Design and Architecture:

• Added .kiro/specs/nifty-stock-analyzer/design.md, outlining a modular pipeline architecture (CLI, data fetcher, analysis engine, export handler), with explicit interfaces for each module and clear separation of concerns.
• Defined data models (StockData, AnalysisResult) and correctness properties, ensuring reliability and traceability from requirements to implementation.

Testing Strategy:

• Established a dual testing approach using both unit tests (pytest) and property-based tests (Hypothesis), with test coverage targets and mapping of tests to correctness properties.

Error Handling and Performance:

• Documented error isolation, retry strategies, and graceful degradation for network, data, and filesystem errors, as well as performance expectations and optimization strategies.

Dependencies and Future Enhancements:

• Specified required Python versions and third-party libraries, and outlined potential future features for extensibility.