Add Migration page

Author: dvoituron

examples/Demo/FluentUI.Demo.Client/Documentation/Components/TreeView/FluentTreeView.md

@@ -135,3 +135,7 @@ For example, if you want to use a mixed checkbox, you can use the `ItemTemplate`
 ## Class TreeViewItem
 
 {{ API Type=TreeViewItem Properties=All }}
+
+## Migrating to v5
+
+{{ INCLUDE File=MigrationFluentTreeView }}

examples/Demo/FluentUI.Demo.Client/Documentation/GetStarted/Migration/MigrationFluentTreeView.md

@@ -0,0 +1,13 @@
+---
+title: Migration FluentTreeView
+route: /Migration/TreeView
+hidden: true
+---
+
+### New properties
+  `Appearance`,  `HideSelection`, `MultipleSelectionVisibility`,
+  `SelectedId`, `SelectedItems`, `SelectionMode`, `Size` are new properties.
+
+### Removed properties💥
+  - The `RenderCollapsedNodes` property has been removed.
+  Use `LazyLoadItems` instead.