Provides a mechanism to add a preference page to customize welcome.

## Package Specification

This package only contains one class, `org.eclipse.ui.intro.universal.ExtensionFactory`. It provides product developers the ability to add a preference page to customize the welcome layout and generate an `introData.xml` file to be included in their final product. The class should only be reference from a `plugin.xml` file. For example usage see `org.eclipse.platform/plugin.xml`. The preference page is included in the Eclipse SDK and can be found under "General -> Welcome".