Fix: scrollHeight example (#36440)

* Fix: scrollHeight example

* Update files/en-us/web/api/element/scrollheight/index.md

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

* Update index.md

* Fix: Code alignment

* Update files/en-us/web/api/element/scrollheight/index.md

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

files/en-us/web/api/element/scrollheight/index.md

@@ -175,7 +175,8 @@ const veryImportantRead = document.getElementById("very-important-read");
 // Check if user has scrolled the element to the bottom
 function isRead(element) {
   return (
-    element.scrollHeight - Math.round(element.scrollTop) <= element.clientHeight
+    Math.abs(element.scrollHeight - element.clientHeight - element.scrollTop) <=
+    1
   );
 }