Add lazy loading on images

src/components/atoms/Image.svelte

@@ -9,6 +9,7 @@
     export let sizes: any = {}
     export let fit: string = 'inside'
     export let format: string = 'jpg'
+    export let lazy: boolean = true
 
     // TODO:
     // - sizes
@@ -22,5 +23,6 @@
         width={width}
         height={height}
         alt={alt}
+        loading={lazy ? 'lazy' : undefined}
     />
 </picture>