Users may not know they can switch slides with → and ← keys. We need to let them know, especially since we prevented the Tab key from working within the carousel.
The best way is to add help text that tells a users they can use → and ← keys to switch slides.
To add this help text, we need to add the following HTML:
<section class="carousel">
<!-- ... -->
<div class="carousel__overlay">
Use ← and → to switch slides.
</div>
</section>