Fix the router and stub out a number of crates to get compiling

examples/optional_props.rs

@@ -10,7 +10,7 @@ fn main() {
     dioxus_desktop::launch(app);
 }
 
-fn app(cx: Scope) -> Element {
+fn app() -> Element {
     cx.render(rsx! {
         Button {
             a: "asd".to_string(),