Wasm target check before build (#1689)

* Add `rustup show` check for wasm32 target

* better place for check

* fmt

* clippy fmt

packages/dioxus-tui/examples/colorpicker.rs

@@ -15,21 +15,21 @@ fn app(cx: Scope) -> Element {
     let mapping: DioxusElementToNodeId = cx.consume_context().unwrap();
     // disable templates so that every node has an id and can be queried
     cx.render(rsx! {
-        div{
+        div {
             width: "100%",
             background_color: "hsl({hue}, 70%, {brightness}%)",
             onmousemove: move |evt| {
                 if let RenderReturn::Ready(node) = cx.root_node() {
-                    if let Some(id) = node.root_ids.borrow().get(0).cloned() {
+                    if let Some(id) = node.root_ids.borrow().first().cloned() {
                         let node = tui_query.get(mapping.get_node_id(id).unwrap());
-                        let Size{width, height} = node.size().unwrap();
+                        let Size { width, height } = node.size().unwrap();
                         let pos = evt.inner().element_coordinates();
-                        hue.set((pos.x as f32/width as f32)*255.0);
-                        brightness.set((pos.y as f32/height as f32)*100.0);
+                        hue.set((pos.x as f32 / width as f32) * 255.0);
+                        brightness.set((pos.y as f32 / height as f32) * 100.0);
                     }
                 }
             },
-            "hsl({hue}, 70%, {brightness}%)",
+            "hsl({hue}, 70%, {brightness}%)"
         }
     })
 }