* fix path to gnome-mpv * fix document viewer index * start xfburn * fix file name capitilization * cleanup bad filename. * add tweaking your desktop chapter blurb. * add screenshots for pavucontrol and xfburn * add screenshot for abiword and evince * add screenshot for simple-scan * Fix double of abiword and write section for gnumeric * Prepend chapter in 3.2 for consistency * add screenshot portion