Update article.md

There has to be a scary CPU-intensive task here, otherwise the example wouldn't make sense. Hence the suppression of "can";
I have also removed "actually" because in this context it would be interpreted as "to your surprise", which is not the case here

1-js/06-advanced-functions/09-call-apply-decorators/article.md

@@ -75,7 +75,7 @@ let worker = {
   },
 
   slow(x) {
-    // actually, there can be a scary CPU-heavy task here  
+    // scary CPU-heavy task here  
     alert("Called with " + x);
     return x * this.someMethod(); // (*)
   }