Fix up paths on dnf systems, e.g. fedora.

linux-game-manager.sh

@@ -522,6 +522,8 @@ case "${game}" in
             elif command -v dnf &> /dev/null ; then
                 sudo dnf copr enable nalika/gzdoom
                 sudo dnf -q -y install freedoom gzdoom
+                sudo mkdir -p /usr/share/games
+                sudo ln -s /usr/share/doom /usr/share/games/doom
             else
                 dialog --backtitle "Linux Game Manager" --msgbox "No supported package managers found. Please install the freedoom and gzdoom packages manually." -1 -1
                 exit 0