Added quicknav usage and specs pages to the site

[raquelarrojo]

Checklist (Check off all the items before submitting)

• [x] Build process is done without errors and all tests pass in /lib directory.
• [x] Self-reviewed the code prior to submitting.
• [x] Meets accessibility standards.
• [x] Added/updated documentation to /website as needed.
• [x] Added/updated tests as needed.

Purpose Usage and specifications quick nav pages added to the site.

Description Usage and specifications quick nav pages added to the site.

Closes #1475