Improvements to Halstack documentation site

[GomezIvann]

Checklist

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

Description
Summary of the updates made to Halstack's main site:

1. New GitHub link was added at the bottom of the sidenav of the repository.

2. New icons added for the edit and report links at the DocFooter component.

3. New UXPin section in /the introduction page, replacing the older section referencing Adobe XD assets.