feat(components): add ListBox

Closes #88

src/components/ListBox/ListBox.svelte

@@ -0,0 +1,33 @@
+<script>
+  let className = undefined;
+  export { className as class };
+  export let size = undefined;
+  export let type = 'default';
+  export let disabled = false;
+  export let invalid = false;
+  export let invalidText = '';
+  export let open = false;
+  export let light = false;
+  export let style = undefined;
+
+  import { cx } from '../../lib';
+</script>
+
+<div
+  role="listbox"
+  tabindex="-1"
+  data-invalid={invalid || undefined}
+  class={cx('--list-box', size && `--list-box--${size}`, type === 'inline' && '--list-box--inline', disabled && '--list-box--disabled', open && '--list-box--expanded', light && '--list-box--light', className)}
+  on:keydown
+  on:keydown={event => {
+    if (event.key === 'Escape') {
+      event.stopPropagation();
+    }
+  }}
+  on:click|preventDefault|stopPropagation
+  {style}>
+  <slot />
+</div>
+{#if invalid}
+  <div class={cx('--form-requirement')}>{invalidText}</div>
+{/if}