Add numClass constant to detect.ts

Author: salim laimeche

lib/yolov8n/detect.ts

@@ -3,7 +3,7 @@ import { renderBoxes } from "./renderBox"
 import { yoloLabels } from "./label"
 
 const numClass = yoloLabels.length
-
+//commit
 /**
  * Preprocess image / frame before forwarded into the model
  * @param {HTMLVideoElement|HTMLImageElement} source