Added temporary preview for monochrome white Fedora Ready logo

Following my comment, it's a merge request meant to provide a temporary solution for the white-on-white problem. Plus I fixed the indentation in two SVGs that was standing out to me: when I initially provided you these monochrome logos, I didn't notice this weird formatting error from the Inkscape generator. Feel free to squash this into a single commit!

All the advanced work, like adding classes to UI bundle and checkerboard backgrounds for preview, shall go separately to Fedora Docs upstream.