CREATE documentation for new Somfy component

 - See home-assistant/core#19548

source/_components/cover.somfy.markdown

@@ -0,0 +1,27 @@
+---
+layout: page
+title: "Somfy Cover"
+description: "Instructions on how to integrate Somfy covers into Home Assistant."
+date: 2019-01-02 12:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: somfy.png
+ha_category: Cover
+ha_release: 0.84
+---
+
+The `somfy` cover platform lets you control covers added to your Tahoma or Connexoon Box in Home Assistant.
+
+Covers will be added automatically. Please refer to the [component](/components/somfy/) configuration on how to setup Somfy.
+
+### Potential duplicate with the Tahoma component
+If you use the [tahoma](/component/tahoma) component, you will have to exclude your cover. Otherwise they will be added twice.
+
+```yaml
+tahoma:
+  username: YOUR_USERNAME
+  password: YOUR_PASSWORD
+  exclude: ['rts:RollerShutterRTSComponent','rts:CurtainRTSComponent','rts:BlindRTSComponent','rts:VenetianBlindRTSComponent','rts:DualCurtainRTSComponent','rts:ExteriorVenetianBlindRTSComponent','io:ExteriorVenetianBlindIOComponent','io:RollerShutterUnoIOComponent','io:RollerShutterWithLowSpeedManagementIOComponent','io:RollerShutterVeluxIOComponent','io:RollerShutterGenericIOComponent','io:WindowOpenerVeluxIOComponent','io:VerticalExteriorAwningIOComponent','io:HorizontalAwningIOComponent']
+```

source/_components/somfy.markdown

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+---
+layout: page
+title: "Somfy"
+description: "Instructions on how to setup the Somfy hub within Home Assistant."
+date: 2019-01-02 12:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: somfy.png
+ha_category: Hub
+ha_iot_class: "Cloud Polling"
+ha_release: 0.84
+---
+
+The Somfy component will allow users to integrate their Somfy devices into Home Assistant using the [official API](https://developer.somfy.com/somfy-open-api/apis), unlike the [Tahoma](/components/tahoma/).
+
+Check the related components pages for actual devices that are supported.
+
+### {% linkable_title Setting up developer account %}
+To connect Somfy, you need to setup a developer account.
+
+1. Vist [https://developer.somfy.com](https://developer.somfy.com)
+2. Login using your Somfy credentials
+3. Open the *My Apps* menu
+4. Add a new App
+  - App Name: Home Assistant
+  - Callback URL: `<YOUR_HOME_ASSISTANT_URL>/auth/somfy/callback`
+  - Description: Home Assistant instance
+  - Product: Somfy Open API
+5. Once Home Assistant restarted, a notification will ask you to log into your Somfy account.
+
+### {% linkable_title Configuration %}
+```yaml
+somfy:
+  client_id: CONSUMER_KEY
+  client_secret: CONSUMER_SECRET
+```
+
+{% configuration %}
+client_id:
+  description: Your Somfy consumer key.
+  required: true
+  type: string
+client_secret:
+  description: Your Somfy consumer secret.
+  required: true
+  type: string
+{% endconfiguration %}