Doc to Duke Energy sensor (#5644)

* Doc to Duke Energy sensor

* Minor changes

* Remove name

* ✏️ Tiny language tweaks

source/_components/sensor.duke_energy.markdown

@@ -0,0 +1,48 @@
+---
+layout: page
+title: "Duke Energy"
+description: "Instructions on how to set Duke Energy smart meter sensors within Home Assistant."
+date: 2018-07-01 09:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: duke_energy.png
+ha_category: Sensor
+ha_release: "0.73"
+ha_iot_class: "Cloud Polling"
+---
+
+The `duke_energy` sensor platform allows you get the previous days usage for all of your Duke Energy smart meters.
+
+You will only have access to meters listed in your account at [Duke Energy Usage](https://www.duke-energy.com/my-account/usage-analysis).
+
+This supports both electric and gas meters. Along with previous days usage, each sensor will have attributes for the previous bills total usage and average usage.
+
+## {% linkable_title Configuration %}
+
+To enable the sensor, add the following lines to your `configuration.yaml`:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: duke_energy
+    username: YOUR_DUKE_USERNAME
+    password: YOUR_DUKE_PASSWORD
+```
+
+{% configuration %}
+username:
+  description: Your Duke Energy username
+  required: true
+  type: string
+password:
+  description: Your Duke Energy password
+  required: true
+  type: string
+{% endconfiguration %}
+
+
+<p class='note'>
+Meter usage isn't updated until mid-morning. Prior to updating your meter will report 0 for usage starting at midnight. The API is only called to update every 2 hours from startup time.
+</p>