add svelte app.

webapp/src/components/Comment.svelte

@@ -0,0 +1,60 @@
+<script>
+  import fromUnixTime from "date-fns/fromUnixTime";
+  import formatDistanceToNow from "date-fns/formatDistanceToNow";
+  export let story;
+  export let comment;
+  export let showComments = true;
+  export let dateString = formatDistanceToNow(fromUnixTime(comment.date), {
+    addSuffix: true,
+  });
+  const author = comment.author.replace(" ", "");
+  export let id = `${author}-${comment.date}`;
+
+  export function toggleComments() {
+    showComments = !showComments;
+  }
+</script>
+
+<style>
+  .comment-author {
+  }
+  .comment-text {
+    padding: 0 0.5rem;
+    color: #333;
+  }
+  .comment-children {
+    margin-left: 1rem;
+    padding-left: 1rem;
+    border-left: solid 1px #000;
+  }
+  .link-button {
+    background: none;
+    border: none;
+    padding: 0 0.1rem;
+    color: inherit;
+    cursor: pointer;
+  }
+</style>
+
+<div class="comment" id="comment-{id}">
+  <div class="comment-author">
+    {comment.author}
+    |
+    <a href="{story.id}#comment-{id}">{dateString}</a>
+    {#if comment.comments.length}
+      <button
+        class="link-button"
+        on:click={toggleComments}>[{showComments ? '-' : '+'}]</button>
+    {/if}
+  </div>
+  <div class="comment-text">
+    {@html comment.text}
+  </div>
+  {#if showComments && comment.comments.length}
+    <div class="comment-children">
+      {#each comment.comments as child}
+        <svelte:self {story} comment={child} />
+      {/each}
+    </div>
+  {/if}
+</div>