Add config option to select UPower device based on device model.

man/waybar-upower.5.scd

@@ -17,6 +17,12 @@ compatible devices in the tooltip.
 	The battery to monitor. Refer to the https://upower.freedesktop.org/docs/UpDevice.html#UpDevice--native-path ++
 	Can be obtained using `upower --dump`
 
+*model*: ++
+	typeof: string ++
+	default: ++
+	The battery to monitor, based on the model. (this option is ignored if *native-path* is given). ++
+	Can be obtained using `upower --dump`
+
 *icon-size*: ++
 	typeof: integer ++
 	default: 20 ++