Carousel: Fix ARIA stuff

src/organisms/Carousel.svelte

@@ -159,7 +159,7 @@
 
 <svelte:window on:keydown={keyboardNav} />
 
-<div class="carousel"
+<div class="carousel" role="region" aria-label="Photos"
     bind:this={scope}
     on:swipe={event => swipe(event.detail.directions)}
 >
@@ -172,8 +172,7 @@
                     class:is-active={id === currentPhoto.id}
                     class:is-next={id === nextPhoto.id}
                     on:click={openFullscreen}
-                    role="group"
-                    aria-roledescription="slide"
+                    role="tabpanel"
                     aria-label="Photo {index + 1} of {photos.length}"
                 >
                     <picture class="gallery__picture">