[Q3-redesign] - Implement the new look and feel for sdv.eclipse.org

This issue is about tracking generic updates to our template for the new l&f:

Implement updates to the

• Header
• Footer
• Typography (font, text and link color, default color scheme)

Details already shared by @mkokabi on #54 (closed)

• The 2 primary colors for buttons, footer, icons, and heading include:
  • Magenta #AA216E
  • Purple #452062
• THE SDV PROJECTS LANDSCAPE section:
  • the secondary color for the top box is #A36A9C
• footer color:
  • #452062

The heading font is Audiowide All the other texts are Roboto

The visual assets are available here: https://gitlab.eclipse.org/eclipsefdn/it/websites/sdv.eclipse.org/uploads/25b01c673cd152870cb9d2bfbb2f6fb7/Visual_Assets_SDV_Website.zip

@oliviergoulet Whenever you get a moment, can you review and confirm that you have everything you need.