Add Discord notification component documentation (#1767)

* Added Discord component page

* Changed description

* Add discord image

source/_components/notify.discord.markdown

@@ -0,0 +1,66 @@
+---
+layout: page
+title: "Discord"
+description: "Instructions how to add Discord notifications to Home Assistant."
+date: 2016-01-14 15:15
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: discord.png
+ha_category: Notifications
+---
+
+The [Discord service](https://discordapp.com/) is a platform for the notify component. This allows components to send messages to the user using Discord.
+
+In order to get a token you need to go to the [Discord My Apps page](https://discordapp.com/developers/applications/me) and create a new application. Once the application is ready, create a bot user. Retreive the client ID and the (hidden) token of your bot for later.
+
+When setting up the application you can use this [icon](https://home-assistant.io/demo/favicon-192x192.png).
+
+### {% linkable_title  Configuration %}
+
+To use Discord notifications, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+notify:
+  - name: NOTIFIER_NAME
+    platform: discord
+    token: A1aB2b.C3cD4d-E5eF6f
+```
+
+Configuration variables:
+
+- **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`.
+- **token** (*Required*): Your bot's token.
+
+### {% linkable_title  Using the bot %}
+Bots can only send messages to servers. To add the bot to a server you are an admin on, use the Discord OAuth2 Authorization page: 
+
+[https://discordapp.com/api/oauth2/authorize?client_id=1234567890&scope=bot&permissions=0](https://discordapp.com/api/oauth2/authorize?client_id=1234567890&scope=bot&permissions=0)
+
+Replace the client ID with the appropriate one from the [Discord My Apps page](https://discordapp.com/developers/applications/me).
+
+Once the bot user has been added to your server, get the channel ID of the channel you want the bot to operate in.
+* In The Discord app go to Settings > Appearance > Check developer mode
+* Right click channel name > Copy ID
+
+This channel ID has to be used as the target when calling the notification service. Multiple channel IDs can be specified, across multiple servers.
+
+#### {% linkable_title Example service payload %}
+
+```json
+{
+  "message": "A message from Home Assistant",
+  "target": [
+    "1234567890",
+    "0987654321"
+  ]
+}
+```
+
+### {% linkable_title  Notes %}
+
+For more information about creating and authorizing bots, visit the [OAuth2 information page](https://discordapp.com/developers/docs/topics/oauth2)
+
+To use notifications effectively, please see the [getting started with automation page](/getting-started/automation/).