feat(navigation): Adding aria-expanded to submenus

[nicholasio]

Description of the Change

Fixes #32

Alternate Designs

Benefits

Possible Drawbacks

Verification Process

Checklist:

• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] All new and existing tests passed.

Applicable Issues

[github-actions[bot]]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: :white_check_mark: success
  • Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[github-actions[bot]]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: :white_check_mark: success
  • Annotations: 0 total

---

^{Report generated by eslint-plus-action}