Summarized 3.0 changes in changelog

docs/en/changelogs/3.0.0.md

@@ -15,6 +15,17 @@
 
 ## Upgrading ##
 
+### Overview
+
+ * Folders: `sapphire/` moved to `framework/`, replace with `FRAMEWORK_DIR` (in PHP) or `$ModulePath(framework)` (in templates). Be sure to update `.htaccess` or `web.config` ([more](#sapphire-rename))
+ * Templates: `<% control %>` replaced by `<% loop %>` and `<% with %>` ([more](/reference/templates-upgrading-guide#control))
+ * `DataObjectSet` is replaced by `DataList`; beware that `DataList->remove()` will delete an entry from the database ([more](#deprecated-classes))
+ * `ComplexTableField` is replaced by `GridField`, which is similar to the `DataObjectManager` extension.
+ * `Director::redirect()` and `Director::redirectBack()` deprecated ([more] (#director-static-functions-deprecated-director-redirect-and-director-redirectback-in-particular)
+ * Changes in ORM, DataObject::get() deprecated ([more](#new-orm-datalist))
+ * `DataObjectDecorator::extraStatics` deprecated ([more](#extensions))
+ * Backend tab paths are shortened: `Root.Content.Main` becomes `Root.Main` ([more](#tab-paths))
+
 ### sapphire renamed to framework {#sapphire-rename}
 
 `sapphire` has been renamed to `framework`.