Added TekSavvy data usage sensor documentation. (#4227)

* Added TekSavvy data usage sensor documentation.

* Fix usage_gb parameters

* Fixed date

* Use configuration section + formulation fix

* Removed tab

* Update 'ha_release'

source/_components/sensor.teksavvy.markdown

@@ -0,0 +1,77 @@
+---
+layout: page
+title: "TekSavvy"
+description: "Instructions on how to integrate TekSavvy data usage within Home Assistant."
+date: 2017-12-17 00:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: teksavvy.png
+ha_category: Sensor
+ha_release: 0.62
+ha_iot_class: "Cloud Polling"
+---
+
+Integrate your [TekSavvy](https://myaccount.teksavvy.com/) account information into Home Assistant.
+
+You can get your API key from 
+https://myaccount.teksavvy.com/ApiKey/ApiKeyManagement
+
+To use your TekSavvy sensor in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: teksavvy
+    api_key: API_KEY
+    total_bandwidth: 400
+    monitored_variables:
+      - usage
+      - usage_gb
+      - limit
+      - onpeak_download
+      - onpeak_upload
+      - onpeak_total
+      - offpeak_download
+      - offpeak_upload
+      - offpeak_total
+      - onpeak_remaining
+```
+
+{% configuration %}
+api_key:
+  description: The TekSavvy API key to access the service.
+  required: true
+  type: string
+total_bandwidth:
+  description: Your bandwidth limit in gigabytes.
+  required: true
+  type: string
+monitored_conditions:
+  description: Conditions to display in the frontend.
+  required: true
+  type: list
+  keys:
+    usage:
+      description: Bandwidth usage (percentage).
+    usage_gb:
+      description: Bandwidth usage (gigabytes).
+    limit:
+      description: Monthly bandwidth limit (gigabytes).
+    onpeak_download:
+      description: Bandwidth used by download outside the unmetered period (gigabytes).
+    onpeak_upload:
+      description: Bandwidth used by upload outside the unmetered period (gigabytes).
+    onpeak_total:
+      description: Total bandwidth used outside the unmetered period (gigabytes).
+    offpeak_download:
+      description: Bandwidth used by download during the unlimited period (gigabytes).
+    offpeak_upload:
+      description: Bandwidth used by upload during the unlimited period (gigabytes).
+    offpeak_total:
+      description: Total bandwidth used during the unlimited period (gigabytes).
+    onpeak_remaining:
+      description: Remaining bandwidth (gigabytes).	  
+{% endconfiguration %}
+