DOCS Add blurbs about several new features to 4.11 changelog

docs/en/04_Changelogs/4.11.0.md

@@ -5,6 +5,8 @@
 - [Regression test and Security audit](#audit)
 - [Dropping support for PHP 7.3](#phpeol)
 - [Features and enhancements](#features-and-enhancements)
+  - [Preview any DataObject in any admin section](#cms-preview)
+  - [Other features](#other-features)
 - [Bugfixes](#bugfixes)
 - [Internal API changes](#internal-api-changes)
 
@@ -21,6 +23,19 @@ In accordance with our [PHP support policy](/Getting_Started/Server_Requirements
 
 ## Features and enhancements {#features-and-enhancements}
 
+### Preview any DataObject in any admin section {#cms-preview}
+
+The CMS preview panel has historically been available for `Versioned` `DataObject`s in the Pages admin section. This has now been expanded to allow any `DataObject` (regardless of whether it uses the`Versioned` extension) to be previewed in any section of the CMS.
+
+This can be used to allow content authors to see the content they are creating in the context it will be presented to users. Example use cases include previewing `DataObject`s which belong to a page (e.g. the [dnadesign/silverstripe-elemental module](https://github.com/silverstripe/silverstripe-elemental) allows previewing elemental blocks which are not inline-editable), and previewing `DataObject`s in a custom admin section, such as templates for emails or system-generated PDF documents.
+
+The [Preview Documentation](https://docs.silverstripe.org/en/4/developer_guides/customising_the_admin_interface/preview/) has been updated with code examples which show how to enable CMS preview on `DataObject`s in a couple of different scenarios.
+
+### Other new features {#other-features}
+
+- A new [AbstractGridFieldComponent](https://api.silverstripe.org/4/SilverStripe/Forms/GridField/AbstractGridFieldComponent.html) class has been added to make it easier to globally add fundamental functionality to `GridFieldComponent`s. All classes packaged with the Silverstripe framework which implement the `GridFieldComponent` interface are subclasses of the new abstract class, making them all `Injectable`. Maintainers of third-party packages which include classes that implement `GridFieldComponent` are encouraged to subclass the `AbstractGridFieldComponent` abstract class.
+- New options have been added to the [dnadesign/silverstripe-elemental module](https://github.com/silverstripe/silverstripe-elemental) to control what content is indexed for searching elemental blocks. see [the documentation](https://github.com/silverstripe/silverstripe-elemental/blob/4/docs/en/searching-blocks.md) for details.
+
 
 ## Bugfixes {#bugfixes}