rephrase section describing old JavaScript code

I felt like this needed a bit if rephrasing.

For example, "But all browsers born in the past 15+ years don’t have any issues" felt a little odd.

After trying to make it more sensible, I felt the same information could be communicated much more simply.

Author: jacobherrington

1-js/02-first-steps/01-hello-world/article.md

@@ -61,7 +61,7 @@ Comments before and after scripts.
     //--></script>
     ```
 
-    These comments were supposed to hide the code from an old browser that didn't know about a `<script>` tag. But all browsers born in the past 15+ years don't have any issues. We mention it here, because such comments serve as a sign. If you see that somewhere -- that code is probably really old and not worth looking into.
+    This trick isn't used in modern JavaScript. These comments were used to hide the JavaScript code from old browsers that didn't know about a `<script>` tag. Since browsers born in the last 15 years don't have this issue, this kind of comment can help you identify really old code.
 
 
 ## External scripts