Restyling of front page

From https://etherpad.gnome.org/p/docs-fosdem-2020:

• Restyling of front page
  • Curated top section that links into GNOME Help?
  • Tiles for apps - randomise?
  • Sydsadmin guide at bottom
  • Link to unstable versions at foot of content?

Current preview: https://help-web.openshift.gnome.org/