Document middleware config options

README.md

@@ -73,6 +73,8 @@ More to come soon, you'll have to mostly rely on the example for now.
 
 ### Config
 
+#### Client
+
 Configuration options can be passed to the client by adding querystring parameters to the path in the webpack config.
 
 ```js
@@ -88,6 +90,22 @@ Configuration options can be passed to the client by adding querystring paramete
 * **quiet** - Set to `true` to disable all console logging.
 * **dynamicPublicPath** - Set to `true` to use webpack `publicPath` as prefix of `path`. (We can set `__webpack_public_path__` dynamically at runtime in the entry point, see note of [output.publicPath](https://webpack.github.io/docs/configuration.html#output-publicpath))
 
+#### Middleware
+
+Configuration options can be passed to the middleware by passing a second arugment.
+
+```js
+app.use(require("webpack-hot-middleware")(compiler, {
+    log: false,
+    path: "/__what",
+    heartbeat: 2000
+}));
+```
+
+* **log** - A function used to log lines, pass `false` to disable. Defaults to `console.log`
+* **path** - The path which the middleware will serve the event stream on, must match the client setting
+* **heartbeat** - How often to send heartbeat updates to the client to keep the connection alive. Should be less than the client's `timeout` setting - usually set to half its value.
+
 ## How it Works
 
 The middleware installs itself as a webpack plugin, and listens for compiler events.