Add brief documentation and example

Author: dextermb

README.md

@@ -14,7 +14,7 @@ composer require langleyfoxall/react-dynamic-data-table-laravel-api
 
 First, create a new route in your API routes file for the data table response, and point it to a controller.
 
-In this controller method, create a new `DataTableResponder` passing it the model you wish to return data about, and the provided instance of the `Request` object. You can optionally specify changes to the query (such as sorting, or filtering) using the `query` method. You can also change number of records shown per page with the `setPerPage` method.
+In this controller method, create a new `DataTableResponder` passing it the model you wish to return data about, and the provided instance of the `Request` object. You can optionally specify changes to the query (such as sorting, or filtering) using the `query` method. If you want to alter the data before it gets return, such as loading relationships or appending custom attributes you can take advantage of `collectionManipulator`. You can also change number of records shown per page with the `setPerPage` method.
 
 See the example usage below.
 
@@ -28,10 +28,15 @@ class UsersController extends Controller
     public function dataTable(Request $request)
     {
         return (new DataTableResponder(User::class, $request))
-            ->query(function($query) {  // Optional, default: none
+            ->query(function($query) {                                   // Optional, default: none
                 $query->where('name', 'like', 'B%');
             })
-            ->setPerPage(10)            // Optional, default: 15
+            ->collectionManipulator(function (Collection $collection) {  // Optional, default: none
+                $collection->map(function($user) {
+                    $user->name = title_case($user->name);
+                });
+            })
+            ->setPerPage(10)                                             // Optional, default: 15
             ->respond();
     }
 }