iOS, change example.odt -> welcome.odt

It must be changed in the swift code also.

Change-Id: Ide7ccbb89d94f91a9f6e0dbbd7a29035c46f7f4f

ios/LibreOfficeLight/LibreOfficeLight/DocumentController.swift

@@ -66,7 +66,7 @@ class DocumentController: UIViewController, MenuDelegate, UIDocumentBrowserViewC
         super.viewDidAppear(animated)
 
         // Always load the 'welcome' file, as per the android app
-        let res = Bundle.main.url(forResource: "example", withExtension: "odt")
+        let res = Bundle.main.url(forResource: "welcome", withExtension: "odt")
 
         // uncomment for test data in resources until the doc picker works properly
         //let res = Bundle.main.url(forResource: "testdata/2", withExtension: "xlsx")