(#1691) adds usa section page to docs site

[dlescarbeau]

Closes #1691

Pull Request Details

Add description

Closes #

Author PR Checklist

Items that the author of the PR is responsible for checking before submitted the PR.

General:

• [x] I have reviewed the acceptance criteria defined in the ticket and ensured the work has been completed.
• [x] The commit message passes all quality commit message standards.
• [x] Unit tests have been updated or created to reflect any javascript changes.
• [x] Storybook scenarios have been updated or created to reflect any html/css/js changes.

Accessibility:

• [x] WCAG 2.1 Level AA requirements have been met.

Development:

• [x] Any new or updated javascript code has 100% unit test coverage.
• [x] New or updated breakpoints have regression images.
• [x] Breaking changes have been thoroughly documented in the PR.

Product Reviewer PR Checklist

Items the product team is responsible for reviewing.

General:

• [x] There are no unexpected or unapproved regression image changes.

• [x] Functionality of interactive elements meet the acceptance criteria.
• [x] The product is visually and functionally the same across the different browsers.

Accessibility:

• [x] AxeDev Tools: there are no new or outstanding accessibility issues introduced in this PR.
• [x] Lighthouse: scores have not noticeably decreased during this PR.
• [x] Wave: there are no new errors or contrast errors introduced in this PR.

Design Reviewer PR Checklist

Items the design team is responsible for reviewing. 


General:

• [x] New or updated features introduced in this PR are developed mobile-first.
• [x] Breakpoint changes and regression images match those breakpoints.
• [x] This PR has been tested in all supported browsers at all breakpoints.

Developer Reviewer PR Checklist

Items the development team is responsible for reviewing.

General:

• [x] New code passes code quality standards set by industry standards.
• [x] The expected Storybook stories have been added or updated for the new or updated feature.
• [ ] The expected unit tests have been added or updated for the new or updated feature.

Accessibility:

• [x] VoiceOver: Described content matches with what was expected.
• [x] Keyboard navigation: new or updated features and content are navigable via the keyboard.

[github-actions[bot]]

Viewing Information

• The documentation site
• NCIDS JS Documentation
• The storybook site
• The example site

[github-actions[bot]]

Viewing Information

• The documentation site
• NCIDS JS Documentation
• The storybook site
• The example site

[andyvanavery31]

In addition to Bryan's points:

• We need a <ul> at the parent level of the unordered list in the Modifications section in the table.
• The table heading under Modifications should be "Modifier" not "Variant" to match the section and to match the rest of the component pages