Only show power levels for battery powered things

src/widgets/power.rs

@@ -58,6 +58,14 @@ impl PowerSupply {
                     })
                 })
                 .collect::<Result<_, _>>()?;
+            // Skip things that aren't battery powered
+            if !values
+                .get("POWER_SUPPLY_TYPE")
+                .map(|t| t == &"Battery")
+                .unwrap_or(false)
+            {
+                continue;
+            }
             let cap: u32 = values
                 .get("POWER_SUPPLY_CAPACITY")
                 .unwrap_or(&"0")