add messagebird documentation

source/_components/notify.message_bird.markdown

@@ -0,0 +1,45 @@
+---
+layout: page
+title: "MessageBird"
+description: "Instructions how to add user notifications to Home Assistant."
+date: 2016-03-15 17:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: message_bird.svg
+ha_category: Notifications
+featured: true
+---
+
+The `MessageBird` notification platform sends notifications as SMS messages using [MessageBird](https://www.messagebird.com/) to your mobile phone.
+
+To enable MessageBird notifications in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+notify:
+  platform: message_bird
+  api_key: YOUR_API_KEY
+  name: NOTIFIER_NAME
+  sender: SENDER_NAME
+```
+
+Configuration variables:
+
+- **api_key** (*Required*): Enter the API key for MessageBird. Go to https://www.messagebird.com/ to retrieve your API key.
+- **name** (*Optional*): Setting the optional parameter `name` allows multiple notifiers to be created. The default value is `notify`. The notifier will bind to the service `notify.NOTIFIER_NAME`.
+- **sender** (*Optional*): Setting the optional parameter `sender`. This will be the sender of the SMS. It may be either a telephone number (e.g. `+4915112345678`) or a text with a maximum length of 11 characters. Defaults to `HA`.
+
+### {% linkable_title Usage %}
+
+MessageBird is a notify platform and thus can be controlled by calling the notify service [as described here](/components/notify/). It will send a notification to the specified mobile phone number(s).
+
+#### {% linkable_title Example service payload %}
+
+```json
+{
+  "message": "A message for many people",
+  "target": [ "+49123456789", "+43123456789" ]
+}
+```