move util in a util folder with the sanitizer

site/docs/4.3/getting-started/javascript.md

@@ -134,12 +134,6 @@ Bootstrap's plugins don't fall back particularly gracefully when JavaScript is d
 {% endcapture %}
 {% include callout.html content=callout type="warning" %}
 
-## Util
-
-All Bootstrap's JavaScript files depend on `util.js` and it has to be included alongside the other JavaScript files. If you're using the compiled (or minified) `bootstrap.js`, there is no need to include this—it's already there.
-
-`util.js` includes utility functions and a basic helper for `transitionEnd` events as well as a CSS transition emulator. It's used by the other plugins to check for CSS transition support and to catch hanging transitions.
-
 ## Sanitizer
 
 Tooltips and Popovers use our built-in sanitizer to sanitize options which accept HTML.

site/docs/4.3/getting-started/webpack.md

@@ -21,7 +21,6 @@ import 'bootstrap';
 Alternatively, you may **import plugins individually** as needed:
 
 {% highlight js %}
-import 'bootstrap/js/dist/util';
 import 'bootstrap/js/dist/alert';
 ...
 {% endhighlight %}