Add deCONZ daylight sensor (#5028)

* Add deCONZ daylight sensor

* ✏️ Minor changes

* 🚑 Fixes build issue

* 🚑 Fixes incorrect tag

source/_components/sensor.deconz.markdown

@@ -43,3 +43,28 @@ Entity ids will be sensor.device_name, where device_name is defined in deCONZ. S
   - Xiaomi Smart Home Wireless Switch
 - Temperature Sensor
   - Xiaomi Temperature/Humidity Sensor
+
+#### {% linkable_title deCONZ Daylight Sensor %}
+
+The deCONZ Daylight sensor is a special sensor built into the deCONZ software since version 2.05.12. It is represented in Home Assistant as a sensor called sensor.daylight. The sensor's state value is a string corresponding to the phase of daylight (descriptions below taken from https://github.com/mourner/suncalc, on which the deCONZ implementation is based):
+
+| Sensor State | Description |
+|--------------|-------------|
+| sunrise_start | sunrise (top edge of the sun appears on the horizon) |
+| sunrise_end | sunrise ends (bottom edge of the sun touches the horizon) |
+| golden_hour_1 | morning golden hour (soft light, the best time for photography) |
+| solar_noon | solar noon (sun is in the highest position) |
+| golden_hour_2 | evening golden hour |
+| sunset_start | sunset starts (bottom edge of the sun touches the horizon) |
+| sunset_end | sunset (sun disappears below the horizon, evening civil twilight starts) |
+| dusk | dusk (evening nautical twilight starts) |
+| nautical_dusk | nautical dusk (evening astronomical twilight starts) |
+| night_start | night starts (dark enough for astronomical observations) |
+| nadir | nadir (darkest moment of the night, the sun is in the lowest position) |
+| night_end | night ends (morning astronomical twilight starts) |
+| nautical_dawn | nautical dawn (morning nautical twilight starts) |
+| dawn | dawn (morning nautical twilight ends, morning civil twilight starts) |
+
+The sensor also has an attribute called "daylight" that has the value `true` when the sensor's state is `golden_hour_1`, `solar_noon`, or `golden_hour_2`, and `false` otherwise.
+
+These states can be used in automations as a trigger (e.g., trigger when a certain phase of daylight starts or ends) or condition (e.g., trigger only if in a certain phase of daylight).