Unify web and ggez tour examples 🎉

examples/tour/src/web.rs

@@ -0,0 +1,33 @@
+use futures::Future;
+use iced_web::UserInterface;
+use wasm_bindgen::prelude::*;
+
+use crate::tour::{self, Tour};
+
+#[wasm_bindgen(start)]
+pub fn run() {
+    console_error_panic_hook::set_once();
+    console_log::init_with_level(log::Level::Trace)
+        .expect("Initialize logging");
+
+    let tour = Tour::new();
+
+    tour.run();
+}
+
+impl iced_web::UserInterface for Tour {
+    type Message = tour::Message;
+
+    fn update(
+        &mut self,
+        message: tour::Message,
+    ) -> Option<Box<dyn Future<Output = tour::Message>>> {
+        self.update(message);
+
+        None
+    }
+
+    fn view(&mut self) -> iced_web::Element<tour::Message> {
+        self.view()
+    }
+}