Update alerts.md (#24420)

This document contains the word JavaScript everywhere apart from in one place where it's abbreviated to JS. This just makes sure it's written as JavaScript consistently across the page.

docs/4.0/components/alerts.md

@@ -50,7 +50,7 @@ Alerts can also contain additional HTML elements like headings, paragraphs and d
 Using the alert JavaScript plugin, it's possible to dismiss any alert inline. Here's how:
 
 - Be sure you've loaded the alert plugin, or the compiled Bootstrap JavaScript.
-- If you're building our JS from source, it [requires `util.js`]({{ site.baseurl }}/docs/{{ site.docs_version }}/getting-started/javascript/#util). The compiled version includes this.
+- If you're building our JavaScript from source, it [requires `util.js`]({{ site.baseurl }}/docs/{{ site.docs_version }}/getting-started/javascript/#util). The compiled version includes this.
 - Add a dismiss button and the `.alert-dismissible` class, which adds extra padding to the right of the alert and positions the `.close` button.
 - On the dismiss button, add the `data-dismiss="alert"` attribute, which triggers the JavaScript functionality. Be sure to use the `<button>` element with it for proper behavior across all devices.
 - To animate alerts when dismissing them, be sure to add the `.fade` and `.show` classes.