Sketch the yolo wasm example. (#546)

* Sketch the yolo wasm example.

* Web ui.

* Get the web ui to work.

* UI tweaks.

* More UI tweaks.

* Use the natural width/height.

* Add a link to the hf space in the readme.

candle-examples/examples/yolo-v8/main.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 #[cfg(feature = "mkl")]
 extern crate intel_mkl_src;
 
@@ -156,7 +154,6 @@ struct C2f {
     cv1: ConvBlock,
     cv2: ConvBlock,
     bottleneck: Vec<Bottleneck>,
-    c: usize,
 }
 
 impl C2f {
@@ -173,7 +170,6 @@ impl C2f {
             cv1,
             cv2,
             bottleneck,
-            c,
         })
     }
 }