Add Tuya Sensor docs (#661)

* Add tuya sensor documentation

* Add tuya component ref

* Add tuya sensor to index

* Fix tuya sensor label

* update image link

Co-authored-by: Guillermo Ruffino <glm.net@gmail.com>

components/sensor/tuya.rst

@@ -0,0 +1,49 @@
+Tuya Sensor
+===========
+
+.. seo::
+    :description: Instructions for setting up a Tuya device sensor.
+    :image: tuya.png
+
+The ``tuya`` sensor platform creates a sensor from a tuya component
+and requires :doc:`/components/tuya` to be configured.
+
+.. code-block:: text
+
+    [13:46:01][C][tuya:023]: Tuya:
+    [13:46:01][C][tuya:032]:   Datapoint 1: switch (value: OFF)
+    [13:46:01][C][tuya:032]:   Datapoint 2: switch (value: OFF)
+    [13:46:01][C][tuya:034]:   Datapoint 3: int value (value: 19)
+    [13:46:01][C][tuya:034]:   Datapoint 4: int value (value: 17)
+    [13:46:01][C][tuya:034]:   Datapoint 5: int value (value: 0)
+    [13:46:01][C][tuya:036]:   Datapoint 7: enum (value: 1)
+    [13:46:01][C][tuya:046]:   Product: '{"p":"ynjanlglr4qa6dxf","v":"1.0.0","m":0}'
+
+On this controller, the datapoint 5 represents the countdown timer in minutes
+which is what we are interested in reading using this platform.
+
+Based on this, you can create the sensor as follows:
+
+.. code-block:: yaml
+
+    # Create a sensor
+    sensor:
+      - platform: "tuya"
+        name: "MySensor"
+        sensor_datapoint: 5
+
+Configuration variables:
+------------------------
+
+- **id** (*Optional*, :ref:`config-id`): Manually specify the ID used for code generation.
+- **name** (**Required**, string): The name of the sensor.
+- **sensor_datapoint** (**Required**, int): The datapoint id number of the sensor.
+- All other options from :ref:`Sensor <config-sensor>`.
+
+See Also
+--------
+
+- :doc:`/components/tuya`
+- :doc:`/components/sensor/index`
+- :apiref:`tuya/sensor/tuya_sensor.h`
+- :ghedit:`Edit`

index.rst

@@ -155,6 +155,7 @@ Sensor Components
     TMP117, components/sensor/tmp117, tmp117.jpg
     Total Daily Energy, components/sensor/total_daily_energy, sigma.svg
     TSL2561, components/sensor/tsl2561, tsl2561.jpg
+    Tuya Sensor, components/sensor/tuya, tuya.png
     Tx20, components/sensor/tx20, tx20.jpg
     Ultrasonic Sensor, components/sensor/ultrasonic, ultrasonic.jpg
     Uptime Sensor, components/sensor/uptime, timer.svg