docs: update local examples and docs to support new syntaxes

examples/core/async.rs

@@ -5,7 +5,7 @@ fn main() {
     dom.rebuild();
 }
 
-const App: FC<()> = |cx, props| {
+const App: Component<()> = |cx| {
     let id = cx.scope_id();
     // cx.submit_task(Box::pin(async move { id }));