Add 'force_update' (#4221)

source/_components/sensor.mqtt.markdown

@@ -25,14 +25,40 @@ sensor:
     state_topic: "home/bedroom/temperature"
 ```
 
-Configuration variables:
+{% configuration %}
-
+state_topic:
-- **state_topic** (*Required*): The MQTT topic subscribed to receive sensor values.
+  description: The MQTT topic subscribed to receive sensor values.
-- **name** (*Optional*): The name of the sensor. Default is 'MQTT Sensor'. 
+  required: true
-- **qos** (*Optional*): The maximum QoS level of the state topic. Default is 0.
+  type: string
-- **unit_of_measurement** (*Optional*): Defines the units of measurement of the sensor, if any.
+name:
-- **expire_after** (*Optional*): Defines the number of seconds after the value expires if it's not updated. Default is 0 (=never expire).
+  description: Name of the MQTT sensor.
-- **value_template** (*Optional*): Defines a [template](/docs/configuration/templating/#processing-incoming-data) to extract a value from the payload.
+  required: false
+  type: string
+  default: MQTT Sensor
+qos:
+  description: The maximum QoS level of the state topic.
+  required: false
+  type: int
+  default: 0
+unit_of_measurement:
+  description: Defines the units of measurement of the sensor, if any.
+  required: false
+  type: string
+expire_after:
+  description: Defines the number of seconds after the value expires if it's not updated.
+  required: false
+  type: int
+  default: 0
+value_template:
+  description: "Defines a [template](/docs/configuration/templating/#processing-incoming-data) to extract the value."
+  required: false
+  type: template
+force_update:
+  description: Sends update events even if the value hasn't changed. Useful if you want to have meaningful value graphs in history.
+  reqired: false
+  type: boolean
+  default: False
+{% endconfiguration %}
 
 ## {% linkable_title Examples %}