Update Fedora logos

[why]
Since 2021 Fedora has a new logo.

[how]
Take SVG from Wikipedia page as suggested by Issue #64 (as no logo can
be downloaded directly from Fedora, and they seem to still fight
replacing it everywhere on their own pages).

Note that the logo's bounding box is oblong, although it is based on a
circle? I kept that.

Create simple inverse logo from that.

Fixes #64
Closes #74 (is obsolete then)

Signed-off-by: Fini Jastrow <[email protected]>