Add Rendering Changes for 12.0 (#3347)

* docs(common): Add Rendering changes for version 12

* Add Chat changes

* Move to correct place

Author: dimodi

upgrade/rendering-changes/12-0-0.md

@@ -0,0 +1,22 @@
+---
+title: 12.0.0
+description: Handle the rendering changes in the 12.0.0 release of the Telerik UI for Blazor components.
+page_title: Rendering Changes in the 10.0.0 Release
+slug: rendering-changes-in-12-0-0
+position: 955
+---
+
+# Rendering Changes in 12.0.0
+
+## Chat
+
+The `div.k-message-list` element no longer renders a `k-avatars` CSS class.
+
+## TabStrip
+
+The `li.k-tabstrip-item` elements no longer render a `k-item` CSS class.
+
+## See Also
+
+* [Use best practices when overriding theme styles](slug:themes-override#best-practices)
+* [Breaking changes in Telerik UI for Blazor 10.0.0](slug:changes-in-10-0-0)

upgrade/rendering-changes/list.md

@@ -10,6 +10,7 @@ position: 0
 
 As the Telerik UI for Blazor matures we will continuously optimize the HTML rendering and the usage of CSS classes. The rendering changes only affect the styling of the components if the application [overrides the built-in CSS styles](slug:themes-override) or uses an outdated [custom theme](slug:themes-customize). This article tracks the product versions with rendering changes.
 
+* [12.0.0](slug:rendering-changes-in-12-0-0)
 * [10.0.0](slug:rendering-changes-in-10-0-0)
 * [9.0.0](slug:rendering-changes-in-9-0-0)
 * [7.0.0](slug:rendering-changes-in-7-0-0)