docs(readme) Add webpack section to README file

### Rationale

It might not be clear enough to library users (especially those using wrapper libraries) that webpack has to know how to resolve
symbols that are not fully compatible with ES6 import

README.md

@@ -123,6 +123,29 @@ noUiSlider.create(slider, {
 });
 ```
 
+Webpack
+-------
+In order to use this with webpack, the easiest way to work with it is by using the [`ProvidePlugin`](https://webpack.js.org/plugins/provide-plugin/):
+
+```javascript
+// webpack.config.js
+var webpack = require('webpack');
+...
+plugins: [
+	new webpack.ProvidePlugin({
+		noUiSlider: 'nouislider'
+	})
+]
+...
+```
+
+If you're using ES6 imports, a simple [import with side effect](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import#Import_a_module_for_its_side_effects_only)
+is enough:
+
+```
+import 'nouislider';
+```
+
 Browser support
 ---------------