Fix socket name in app

README.md

@@ -200,9 +200,9 @@ const chat = new IO({
 
 chat.attach( app )
 
-app.chat.use( ... )
-app.chat.on( ... )
-app.chat.broadcast( ... )
+app.io.use( ... )
+app.io.on( ... )
+app.io.broadcast( ... )
 ```
 
 The attachment is configurable if you don’t want to muddy the `app` object with all your namespaces.