Less clumsy configuration for desktop and mobile (#553)

* chore: dont use prebuilt builder pattern for configuring desktop

* chore: use regular config pattern for web

* Chore: update docs too

* chore: clean up some warnings

examples/hydration.rs

@@ -10,12 +10,13 @@
 //! proof-of-concept for the hydration feature, but you'll probably only want to use hydration for the web.
 
 use dioxus::prelude::*;
+use dioxus_desktop::Config;
 
 fn main() {
     let vdom = VirtualDom::new(app);
     let content = dioxus_ssr::render_vdom_cfg(&vdom, |f| f.pre_render(true));
 
-    dioxus_desktop::launch_cfg(app, |c| c.with_prerendered(content));
+    dioxus_desktop::launch_cfg(app, Config::new().with_prerendered(content));
 }
 
 fn app(cx: Scope) -> Element {