Add note about app(props, container).

Author: jorgebucaran

docs/README.md

@@ -54,7 +54,14 @@ app({
 
 In this example we are using a `<script>` tag to download the minified library from a CDN. In a production environment you will probably be using a module bundler to build your application instead.
 
-Hyperapp applications consist of a single `app()` call. This function initializes and renders the application to the page. The `h()` function returns a virtual node tree. A virtual node is a JavaScript object that describes a DOM tree. Hyperapp consumes this object to update the DOM.
+Hyperapp applications consist of a single `app()` call. This function initializes and renders the application to document.body. You can select a different container too.
+
+```js
+app(
+  props,
+  document.getElementById("app")
+)
+```
 
 ### State
 
@@ -86,6 +93,8 @@ Returning a new state from an action updates the current state and schedules a v
 The view describes your user interface as a function of the [state](#state).
 Bind user events and [actions](#actions) together to create interactive applications. The view function is called every time we need to re-render the application due to state changes.
 
+The `h()` function returns a virtual node, an object that describes a DOM tree. Hyperapp consumes this object to update the DOM.
+
 Popular alternatives to the built-in `h()` function include [JSX](https://facebook.github.io/jsx/), [Hyperx](https://github.com/choojs/hyperx), [t7](https://github.com/trueadm/t7) and [@hyperapp/html](https://github.com/hyperapp/html).
 
 ```html