do not take into account peripheral device batteries when computing battery charge, fixes #161

.tmux.conf

@@ -253,6 +253,8 @@ run 'cut -c3- ~/.tmux.conf | sh -s _apply_configuration'
 #       ;;
 #     *Linux*)
 #       while IFS= read -r batpath; do
+#         grep -i -q device "$batpath/scope" 2> /dev/null && continue
+#
 #         if [ x"$discharging" != x"true" ]; then
 #           discharging=$(grep -qi "discharging" "$batpath/status" && echo "true" || echo "false")
 #         fi