docs(README.md): update to get a brief overview

* Added "Documentation" section. Ref #128

README.md

@@ -4,21 +4,97 @@
 [![Version][npm-image]][npm-url]
 
 
-## Installation
+## Quick start: SimpleMap
+
+Declare your Google Maps components using React components.
+
+```js
+import {GoogleMap, Marker} from "react-google-maps";
+
+export default function SimpleMap (props) {
+  return (
+    <section style={{height: "100%"}}>
+      <GoogleMap containerProps={{
+          style: {
+            height: "100%",
+          },
+        }}
+        defaultZoom={3}
+        defaultCenter={{lat: -25.363882, lng: 131.044922}}
+        onClick={props.onMapClick}
+      >
+        {props.markers.map((marker, index) => {
+          return (
+            <Marker
+              {...marker}
+              onRightclick={() => props.onMarkerRightclick(index)} />
+          );
+        })}
+      </GoogleMap>
+    </section>
+  );
+}
+```
+
+
+## Documentation
+
+### Rule 1
+
+Define `<GoogleMap>` component in the top level. Use `containerProps`, `containerTagName` to customized the wrapper DOM for the component.
+
+Other components like `<Marker>` belongs to the children of `<GoogleMap>`. You already know this from the example code above.
+
+### Rule 2
+
+Everything in the `Methods` table in the [official documentation](https://developers.google.com/maps/documentation/javascript/3.exp/reference#Marker) of the component could be set via component's *props* directly. For example, a `<Marker>` component has the following *props*:
 
-```sh
-npm i --save react-google-maps
 ```
+animation, attribution, clickable, cursor, draggable, icon, label, opacity, options, place, position, shape, title, visible, zIndex
+```
+
+### Rule 3
 
+Every props mentioned in __Rule 2__ could be either [controlled](https://facebook.github.io/react/docs/forms.html#controlled-components) or [uncontrolled](https://facebook.github.io/react/docs/forms.html#uncontrolled-components) property. Free to use either one depends on your use case.
 
-## Demo/Examples
+### Rule 4
+
+Anything that are inside components' `options` property could __ONLY__ be accessible via `props.options`. It's your responsibility to manage `props.options` object during the React lifetime for your component. My suggestion is, always use __Rule 3__ if possible. Only use `options` when it's necessary.
+
+### Check the examples
 
 Static hosted [demo site][demo] on GitHub. The code is located under [examples/gh-pages][examples_gh_pages] folder.
 
 
 ## Usage
 
-This module requires to be bundled with build tools like [webpack][webpack] or browserify.
+`react-google-maps` requires __React 0.14__
+
+```sh
+npm install --save react-google-maps
+```
+
+All components are available on the top-level export.
+
+```js
+import { GoogleMap, Marker, SearchBox } from "react-google-maps";
+```
+
+### Optimize bundle size
+
+You could of course import from individual modules to save your [webpack][webpack]'s bundle size.
+
+```js
+import GoogleMap from "react-google-maps/lib/GoogleMap"; // Or import {default as GoogleMap} ...
+```
+
+### Additional Addons
+
+Some addons component could __ONLY__ be accessible via direct import:
+
+```js
+import InfoBox from "react-google-maps/lib/addons/InfoBox";
+```
 
 
 ## Development
@@ -51,7 +127,7 @@ docker-compose build
 
 ### With Mac
 
-Install `node@^0.12.4`. Then,
+Install `node`. Then,
 
 ```shell
 npm install
@@ -64,7 +140,7 @@ Then open [http://localhost:8080/webpack-dev-server/](http://localhost:8080/webp
 
 ### With Windows
 
-Install `node@^0.12.4`. Then,
+Install `node`. Then,
 
 ```shell
 npm install