Anchor tabs component

[m-akinc]

Pull Request

🤨 Rationale

Addresses #479

👩‍💻 Implementation

• Created nimble-anchor-tabs component with implementation starting from the FAST foundation tabs component.
• Created nimble-anchor-tab component.
• Updated and moved existing styling for nimble-tab into shared patterns/tab location. Shared styling used for nimble-anchor-tab, too.
• Wrote unit tests for both new components. Because the nimble-anchor-tabs component is heavily modified from the original FAST source, I created comprehensive tests of public API and interactions.
• Created Storybook stories
• Updated README table

Angular and Blazor support will be in follow-up PRs

🧪 Testing

Wrote unit tests and tested in Storybook.

✅ Checklist

• I have updated the project documentation to reflect my changes or determined no changes are needed.

[jattasNI]

I reviewed everything except the anchor-tabs files and tests. I'll come back to those but wanted to share initial feedback.

[rajsite]

Wanted to share first pass of discussion, still looking through though