Fix index column name.

yajra/laravel-datatables#1882

Author: yajra

general-settings.md

@@ -37,7 +37,7 @@ The sql generated will be like `column LIKE "%k%e%y%w%o%r%d%"` when set to `true
 DataTables internal index id response column name.
 
 ```php
-'index_column' => 'DT_Row_Index',
+'index_column' => 'DT_RowIndex',
 ```
 
 <a name="engines"></a>

index-column.md

@@ -16,4 +16,4 @@ Route::get('user-data', function() {
 ```
 
 Using `addIndexColumn` will add another column on your response with a column name that is set on [`index_column`](/docs/{{package}}/{{version}}/general-settings#index-column) configuration.
-The default index column name is `DT_Row_Index`
+The default index column name is `DT_RowIndex`