Added Documentation for OpenEVSE sensor. (#1947)

* Added Documentation for OpenEVSE sensor.

* Added ha_release.

source/_components/sensor.openevse.markdown

@@ -0,0 +1,40 @@
+---
+layout: page
+title: "OpenEVSE Sensor"
+description: "Instructions how to integrate a WiFi-equipped OpenEVSE Charging station with Home Assistant"
+date: 2017-02-02 22:09
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: openevse.png
+ha_category: Sensor
+ha_release: "0.38"
+---
+
+
+This `openevse` sensor platform pulls data from an [OpenEVSE](https://www.openevse.com/) Charging station equipped with an ESP8266-based wifi connection.
+
+To enable this sensor in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yml entry
+sensor:
+  - platform: openevse
+    host: IP_ADDRESS
+    monitored_variables:
+      - status
+```
+
+Configuration variables:
+
+- **api_key** (*Required*): Your Sonarr API key, found in Settings > General in the Sonarr Web UI.
+- **host** (*Required*): The IP address or hostname of your charger
+- **monitored_variables** array (*Required*): Conditions to display on the frontend.
+  - **status**: The status of the charger (i.e., "Connected", "Charging", etc.)
+  - **charge_time**: The number of minutes the charging has been charging, or 0 if it is not charging.
+  - **rtc_temp**: The temperature reported by the real time clock sensor, or 0 if the sensor is not installed.
+  - **ir_temp**: The temperature reported by the IR remote sensor, or 0 if the sensor is not installed.
+  - **ambient_temp**: The temperature reported by the ambient sensor, or 0 if the sensor is not installed.
+  - **usage_session**: The energy usage for the current charging session.
+  - **usage_total**: The total energy usage for the device.