Silverblue pages should use the Silverblue logo consistently

This is the visual Identity that we have right now for Silverblue and it is well used, in the Ananconda installer, etc.

This is reverse of #207 (closed).

If we want to use another logo then we should wait until we have a replacement to remove the old one.

All other Fedora Editions have their own logos. Silverblue should have its own too.