fix: broaden Trade Study scope in package README

[jc-macdonald]

This pull request updates the project description in the README.md file to clarify and broaden the scope of the tool. The revised language emphasizes that the framework supports scoring and evaluating a variety of design decisions, not just scientific models, and provides more concrete examples of its applications.

Documentation improvements:

• Expanded the project description to highlight that the framework can be used to evaluate model formulations, solver choices, measurement strategies, and other design decisions, in addition to scientific models.
• Clarified that the scoring is performed against known ground truth and that the framework supports observable-based scoring, multi-objective Pareto optimization, and Bayesian model stacking.