Also fix the aspect ratio in the wasm example. (#556)

* Also fix the aspect ratio in the wasm example.

* Add the yolo lib.

* Update the build script.

candle-wasm-examples/yolo/src/bin/m.rs

@@ -0,0 +1,25 @@
+use candle_wasm_example_yolo::worker::Model as M;
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub struct Model {
+    inner: M,
+}
+
+#[wasm_bindgen]
+impl Model {
+    #[wasm_bindgen(constructor)]
+    pub fn new(data: Vec<u8>) -> Result<Model, JsError> {
+        let inner = M::load_(&data)?;
+        Ok(Self { inner })
+    }
+
+    #[wasm_bindgen]
+    pub fn run(&self, image: Vec<u8>) -> Result<String, JsError> {
+        let boxes = self.inner.run(image)?;
+        let json = serde_json::to_string(&boxes)?;
+        Ok(json)
+    }
+}
+
+fn main() {}