Added more documentation for nested gridfields.

README.md

@@ -18,6 +18,8 @@ This module provides a number of useful grid field components:
   features.
 * `GridFieldTitleHeader` - a simple header which displays column titles.
 * `GridFieldConfigurablePaginator` - a paginator for GridField that allows customisable page sizes.
+* `GridFieldNestedForm` - allows nesting of GridFields for managing relation records directly within
+  a parent GridField.
 
 ## Installation
 

docs/en/index.md

@@ -166,3 +166,32 @@ $grid->getConfig()->addComponent(GridFieldNestedForm::create());
 // Usage with custom relation
 $grid->getConfig()->addComponent(GridFieldNestedForm::create()->setRelationName('MyRelation'));
 ```
+
+You can define your own custom GridField config for the nested GridField configuration by implementing a `getNestedConfig`
+on your nested model (should return a `GridField_Config` object).
+```php
+class NestedObject extends DataObject
+{
+	private static $has_one = [
+		'Parent' => ParentObject::class
+	];
+
+	public function getNestedConfig(): GridFieldConfig
+	{
+		$config = new GridFieldConfig_RecordViewer();
+		return $config;
+	}
+}
+```
+
+You can also modify the default config (a `GridFieldConfig_RecordEditor`) via an extension to the nested model class, by implementing
+`updateNestedConfig`, which will get the config object as the first parameter.
+```php
+class NestedObjectExtension extends DataExtension
+{
+	public function updateNestedConfig(GridFieldConfig &$config)
+	{
+		$config->removeComponentsByType(GridFieldPaginator::class);
+	}
+}
+```