This removes the sections and associated images from the front page, instead
just using a single splash image. This is an image from blender.org but could
also be an actual splash screen if we want to keep it fresh.
The sections always looked rather messy to me, the mix of text and images is
difficult to scan and duplicates the menu on the left side. Rather than updating
the outdated images, I rather have little information here and instead guide the
user towards the menu.



