Add zwave cover info (#826)

* Add zwave cover info

* Wrong filename

* add rpi_gpio to cover

* Add homematic to cover

* Wrong date and Ha version

* add rfxtrx to cover

* Deprecated warning for garage_door

* Deprecated warning for rollershutter

source/_components/cover.rpi_gpio.markdown

@@ -0,0 +1,48 @@
+---
+layout: page
+title: "Raspberry Pi Cover"
+description: "Instructions how to setup the Raspberry Pi covers within Home Assistant."
+date: 2016-08-24 14:28
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: raspberry-pi.png
+ha_category: Cover
+ha_release: 0.27
+---
+
+The `rpi_gpio` cover platform allows you to use a Raspberry Pi to control your cover such as Garage doors.
+
+It uses two pins on the Raspberry Pi. 
+- The `state_pin` will detect if the cover is closed, and
+- the `relay_pin` will trigger the cover to open or close.
+
+Although you do not need Andrews Hilliday's software controller when you run Home Assistant, he has written clear instructions on how to hook your garage door & sensors up to your Raspberry Pi, which can be found [here](https://github.com/andrewshilliday/garage-door-controller#hardware-setup).
+
+To enable Raspberry Pi Covers in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+cover:
+  platform: rpi_gpio
+  state_pull_mode: DOWN
+  relay_time: 1
+  covers:
+    - relay_pin: 10
+      state_pin: 11
+      name: 'Left door'
+    - relay_pin: 12
+      state_pin: 13
+      name: 'Right door'
+```
+
+Configuration variables:
+
+- **covers** array (*Required*): List of your doors.
+  - **name** (*Optional*): Name to use in the Frontend.
+  - **relay_pin** (*Required*): The pin of your Raspberry Pi where the relay is connected.
+  - **state_pin** (*Required*): The pin of your Raspberry Pi to retrieve the state.
+  - **state_pull_mode** (*Optional*): The direction the State pin is pulling. It can be UP or DOWN. Default is UP.
+  - **relay_time** (*Optional*): The time that the relay will be on for in seconds. Default is .2 seconds.
+