Docs for Hook (#1490)

* Documentation for Hook
* Fixed spelling
* Added `ha_version` and `ha_iot_class`

source/_components/switch.hook.markdown

@@ -0,0 +1,38 @@
+---
+layout: page
+title: "Hook Switch"
+description: "Instructions on how to integrate the Hook Smart Home Hub into Home Assistant."
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: hook.png
+ha_category: Switch
+ha_iot_class: "Assumed State"
+ha_release: 0.34
+---
+
+The `hook` component allows you to control the [Hook Smart Home Hub](http://www.hooksmarthome.com/) from within Home Assistant.
+
+Hook allows you to control cheap mains electrical outlets, like these ones at [Amazon](https://www.amazon.com/Etekcity-Wireless-Electrical-Household-Appliances/dp/B00DQELHBS). 
+
+In short, Hook is an RF to Wi-Fi bridge, controlling devices that recieve commands at 315MHz and 433MHz. Unfortunately, this does not allow Hook to determine if the command was successful, so the state is assumed.
+
+Hook provides a simple [REST API](https://app.swaggerhub.com/api/rahilj/GetHook_RestAPI/v1). This Home Assistant component reads in devices that have been set up in the official app.
+
+```yaml
+# Example configuration.yaml entry
+-  platform: hook
+   username: <email address>
+   password: !secret hook
+```
+
+Extra debug logging is available, if you need it.
+
+```yaml
+# Example configuration.yaml entry
+logger:
+  default: error
+  logs:
+    homeassistant.components.switch.hook: debug
+```