Use cargo workspaces

web/src/main.rs

@@ -0,0 +1,12 @@
+use yew::prelude::*;
+
+#[function_component(App)]
+fn app() -> Html {
+    html! {
+        <h1>{ "Hello World" }</h1>
+    }
+}
+
+fn main() {
+    yew::start_app::<App>();
+}