Halstack site updates based on the new design tokens

[GomezIvann]

Checklist

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

Description

• Removed /theme-generator page: https://developer.dxc.com/halstack/15/theme-generator/opinionated-theme/
• Removed /themes page: https://developer.dxc.com/halstack/15/principles/themes/
• Updated inner components with new design tokens (Code, TableCode, ExtendedTableCode, HeadingLink, Example, CodeBlock, SidenavLogo, DocFooter, etc).
• Updated document titles and adjusted layout components in the documentation site, replacing rem values with the new design tokens.
• Link font size fix (from fixed to inherited).