set alt on images

src/components/EmbedMedia.svelte

···
 				thumbnail: {
 					src: img('feed_thumbnail', did, cid),
 					...size
-				}
+				},
+				alt: i.alt
 			};
 		})}
 		{#if images.length > 0}

src/components/PhotoSwipeGallery.svelte

···
 			class:hidden-in-grid={isHidden}
 			class:overlay-container={isOverlay}
 		>
-			<img src={thumb.src} alt={img.alt ?? ''} width={thumb.width} height={thumb.height} />
+			<img
+				src={thumb.src}
+				title={img.alt ?? ''}
+				alt={img.alt ?? ''}
+				width={thumb.width}
+				height={thumb.height}
+			/>
 
 			{#if isOverlay}
 				<div class="more-overlay">