Add Entity categories for Home Assistant (#2636)

esphome/components/xiaomi_cgd1/sensor.py

@@ -10,6 +10,7 @@ from esphome.const import (
     DEVICE_CLASS_BATTERY,
     DEVICE_CLASS_HUMIDITY,
     DEVICE_CLASS_TEMPERATURE,
+    ENTITY_CATEGORY_DIAGNOSTIC,
     STATE_CLASS_MEASUREMENT,
     UNIT_CELSIUS,
     UNIT_PERCENT,
@@ -47,6 +48,7 @@ CONFIG_SCHEMA = (
                 accuracy_decimals=0,
                 device_class=DEVICE_CLASS_BATTERY,
                 state_class=STATE_CLASS_MEASUREMENT,
+                entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
             ),
         }
     )