Simple notification framework (#297)

* bonfire notifications working

* make interface to make more extensible

* some docs

* typo

* rename typo

docs/index.md

@@ -129,6 +129,9 @@ title: DnsControl
 				<li>
 					<a href="{{site.github.url}}/unittests">Testing</a>: Unit Testing for you DNS Data
 				</li>
+				<li>
+					<a href="{{site.github.url}}/notifications">Notifications</a>: Be alerted when your domains are changed
+				</li>
 
 			</ul>
 		</div>

docs/notifications.md

@@ -0,0 +1,47 @@
+---
+layout: default
+title: Notifications
+---
+# Notifications
+
+DNSControl has build in support for notifications when changes are made. This allows you to post messages in team chat, or send emails when dns changes are made.
+
+Notifications are written in the [notifications package](https://github.com/StackExchange/dnscontrol/tree/master/pkg/notifications), and is a really simple interface to implement if you want to add
+new types or destinations.
+
+## Configuration
+
+Notifications are set up in your credentials json file. They will use the `notifications` key to look for keys or configuration needed for various notification types.
+
+```
+  "r53": {
+      ...
+    },
+  "gcloud": {
+        ...
+  } ,
+  "notifications":{
+      "bonfire_url": "https://chat.meta.stackexchange.com/feeds/rooms/123?key=xyz"
+  }
+```
+
+You also must run `dnscontrol preview` or `dnscontrol push` with the `-notify` flag to enable notification sending at all.
+
+## Notification types
+
+### Bonfire
+
+This is stack overflow's built in chat system. This is probably not useful for most people.
+
+Configure `bonfire_url` to be the full url including room and api key.
+
+## Future work
+
+Yes, this seems pretty limited right now in what it can do. We didn't want to add a bunch of notification types if nobody was going to use them. The good news is, it should 
+be really simple to add more. We gladly welcome any PRs with new notification destinations. Some easy possibilities:
+
+- Email
+- Slack
+- Generic Webhooks
+
+Please update this documentation if you add anything.