feat(fast-design-system): improve ergonomics of the fast design system

[EisenbergEffect]

Pull Request

📖 Description

Based on community feedback and some potential error cases, I've added a provideFASTDesignSystem function as the default way of getting a design system instance. Additionally, I've made allComponents into a registry itself so that it can be passed directly to the design system. Here's what the code would now be:

provideFASTDesignSystem().register(allComponent);

👩‍💻 Reviewer Notes

This is an additive change to mostly improve ergonomics but to also provide a more standard setup function which we can augment the content of in the future without breaking consumers.

📑 Test Plan

Existing tests passing. New APIs are consumed in the process of running the storybook, and so are validated there.

✅ Checklist

General

• I have included a change request file using $ yarn change
• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

⏭ Next Steps

As soon as this PR is in, we need to do two pretty quick follow up tasks:

• Update the FluentUI Web Components with the same pattern e.g. provideFluentUIDesignSystem()
• Update our documentations to use these functions rather than DesignSystem.getOrCreate()...

[nicholasrice]

way nicer!

[chrisdholt]

Sweet!