Add configschema.json and update README

Author: denolfe

README.md

@@ -21,6 +21,17 @@ This bundle emits the `follower` event for a new follower, and registers the
 `latestFollower` replicant for the latest follower. These have a payload
 consisting of the [Twitch API Follower object](https://github.com/justintv/Twitch-API/blob/master/v3_resources/follows.md#get-usersuserfollowschannels).
 
+## Sample Config
+
+```json
+{
+  "username": "twitchname",
+  "pollInterval": 30
+}
+```
+
+This can also be generated by the [nodecg-cli's](https://github.com/nodecg/nodecg-cli) `defaultconfig` command.
+
 ### Example
 
 ```javascript

configschema.json

@@ -0,0 +1,16 @@
+{
+  "type": "object",
+  "properties": {
+    "username": {
+      "description": "Twitch.tv username",
+      "type": "string",
+      "default": ""
+    },
+    "pollInterval": {
+      "description": "Interval to update followers (seconds)",
+      "type": "integer",
+      "default": 30
+    }
+  },
+  "required": ["username"]
+}