Add docs for Notion (#9665)

* Add docs for Notion

* Reviewer comments

source/_components/notion.markdown

@@ -0,0 +1,41 @@
+---
+layout: page
+title: "Notion"
+description: "How to integrate Notion kits within Home Assistant."
+date: 2019-06-19 20:52
+sidebar: true
+comments: false
+logo: notion.png
+ha_category:
+  - Hub
+  - Binary Sensor
+  - Sensor
+ha_release: 0.96
+ha_iot_class: Cloud Polling
+---
+
+The `Notion` component retrieves data from [Notion](https://getnotion.com) wireless
+home monitoring sensor kits.
+
+## Configuration
+
+To add your Notion kits to your Home Assistant installation, add the following to your
+`configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+notion:
+  username: YOUR_EMAIL_ADDRESS
+  password: YOUR_PASSWORD
+```
+
+{% configuration %}
+username:
+  description: An email address for an active Notion account.
+  required: true
+  type: string
+password:
+  description: The password for the account.
+  required: true
+  type: string
+{% endconfiguration %}