Document modbus light color temperature and brightness support (#37973)

source/_integrations/modbus.markdown

@@ -1239,6 +1239,26 @@ lights:
       required: false
       default: 0x00
       type: integer
+    brightness_address: 
+      description: "Address to read/write color brightness."
+      required: false
+      default: None
+      type: integer
+    color_temp_address:
+      description: "Address to read/write color temperature."
+      required: false
+      default: None
+      type: integer
+    min_temp:
+      description: "Minimal level of color temperature in Kelvin."
+      required: false
+      default: 2000
+      type: integer
+    max_temp:
+      description: "Maximal level of color temperature in Kelvin."
+      required: false
+      default: 7000
+      type: integer
     write_type:
       description: "Type of write request."
       required: false
@@ -1313,6 +1333,22 @@ modbus:
         slave: 2
         address: 14
         write_type: coil
+        brightness_address: 1006
+        verify:
+      - name: "light3"
+        slave: 2
+        address: 14
+        write_type: coil
+        brightness_address: 1006
+        color_temp_address: 2006
+      - name: "light4"
+        slave: 2
+        address: 14
+        write_type: coil
+        brightness_address: 1006
+        color_temp_address: 2006
+        min_temp: 2500
+        max_temp: 5500
         verify:
       - name: "Register1"
         address: 11