Moved some modules and added documentation

scrbl/wv-dialog.scrbl

@@ -5,12 +5,13 @@
           scribble/core
           (for-label racket/base
                      racket/class
-                     "../private/wv-window.rkt"))
+                     "../wv-dialog.rkt"
+                     "../wv-window.rkt"))
 
 @title{wv-dialog}
 @author[@author+email["Hans Dijkema" "hans@dijkewijk.nl"]]
 
-@defmodule[wv-dialog]
+@defmodule[racket-webview/wv-dialog]
 
 Dialog-window wrapper built on top of @racket[wv-window%].