Update hz.md

snippets/hz.md

@@ -3,7 +3,9 @@
 Returns the number of times a function executed per second. 
 `hz` is the unit for `hertz`, the unit of frequency defined as one cycle per second.
 
-Use `window.performance.now()` to get the difference in milliseconds before and after the iteration loop to calculate the time elapsed executing the function `iterations` times. Return the number of cycles per second by converting milliseconds to seconds and dividing it by the time elapsed. Omit the second argument, `iterations`, to use the default of 100 iterations.
+Use `performance.now()` to get the difference in milliseconds before and after the iteration loop to calculate the time elapsed executing the function `iterations` times. 
+Return the number of cycles per second by converting milliseconds to seconds and dividing it by the time elapsed. 
+Omit the second argument, `iterations`, to use the default of 100 iterations.
 
 ```js
 const hz = (fn, iterations = 100) => {