Including `xfce4-panel-profiles` into the list of dependencies of README.md

Release 3.0

As i tried to use the Chicago95 installer, i noticed that at the last item in the list of things the installer should change, namely the option to let the installer change the panel settings, the checkbox is greyed out and hovering over it told me to install the `xfce4-panel-profiles` package. I saw this behavior on both Xubuntu and Manjaro Xfce.

I ask myself why two distributions having XFCE as their desktop don't include this package. Questions aside, i would be pleased to see the `xfce4-panel-profiles` package added as a dependency in the README.md.