Enhance NOS skill assessment package’s user and developer experience

The NOS OFS Skill Assessment package is a Python-based framework used to evaluate operational forecast systems (OFS) through observation retrieval, model processing, skill computation, and visualization. As the system continues to evolve, gaps in automated testing, continuous integration, and user-facing validation create challenges in maintaining reliability and usability. This project focuses on improving developer and user experience without modifying the scientific computation pipeline. The primary objectives are to introduce a GitHub Actions-based CI workflow, expand deterministic unit test coverage across core modules, and enhance the existing tkinter-based GUI with structured parameter grouping, validation logic, and contextual tooltips derived from existing argument definitions. In addition, the project will improve contributor onboarding by restructuring documentation using MkDocs. A lightweight, read-only dashboard will also be explored to organize and present outputs from completed skill assessment runs, providing a concise operational overview.