[chore] Unify directory naming

[haworku]

Does your feature request relate to a specific USWDS component or github issue?
#1929

Is your feature request related to a problem? Please describe.

As @brandonlenz points out - We don't seem to have a unified pattern for how we name folders when double nesting things, (e.g. in this case SummaryBox/SummaryBox, or Footer/Footer or card/Card). JS, React, and TS are pretty un-opinionated about this, so none are wrong. Let's converge on a naming convention.

Describe the solution you'd like

If a folder does not directly contain a component file, it should be lowercased. If a folder contains a matching component file it should be CapitalCased.

Examples:summarybox/SummaryBox/SummaryBox.tsx versus Address/Address.tsx)

Describe alternatives you've considered

• kebab-case, but that's pretty uncommon React folder structures.
• camelCase is a common JS convention to consider. However, chose lowercased bc it was already suggested and it helps de-emphasize the organizational folders even further.

[werdnanoslen]

@haworku would #2728 resolve this issue?