Don't include deleted or empty articles in list

tests/fixtures/article-deleted.json

@@ -0,0 +1,9 @@
+{
+  "content": "",
+  "created_at": 1716761766,
+  "id": "ae83c3e23e11db5fd0e6dacaece38847451e81d1429e4182a0cadd409bdce30f",
+  "kind": 30023,
+  "pubkey": "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d",
+  "sig": "6c21eba5324af302dfbfb9dadfc2d067646a3594ffed02d2528cca8ee0f7c16b9ffb3dc640420304882be94e789d93191d830108ac52d57b2e72445025e433b2",
+  "tags": [["d", "66674915"], ["deleted"]]
+}

tests/models/article_test.ts

@@ -1,17 +1,18 @@
 import { beforeAll, describe, it } from "@std/testing/bdd";
 import { expect } from "@std/expect";
-import { NostrEvent as NEvent } from "@nostrify/nostrify";
 import Article from "../../models/article.ts";
 
 describe("Article", () => {
-  let articleEvent: NEvent;
   let article: Article;
+  let deletedArticle: Article;
 
   beforeAll(() => {
-    articleEvent = JSON.parse(
+    article = new Article(JSON.parse(
       Deno.readTextFileSync("tests/fixtures/article-1.json"),
-    );
-    article = new Article(articleEvent);
+    ));
+    deletedArticle = new Article(JSON.parse(
+      Deno.readTextFileSync("tests/fixtures/article-deleted.json"),
+    ));
   });
 
   describe("#identifier", () => {
@@ -58,6 +59,13 @@ describe("Article", () => {
     });
   });
 
+  describe("#isDeleted", () => {
+    it("returns a boolean based on the 'deleted' tag", () => {
+      expect(article.isDeleted).toEqual(false);
+      expect(deletedArticle.isDeleted).toEqual(true);
+    });
+  });
+
   describe("#naddr", () => {
     it("returns a bech32 addressable event ID", () => {
       expect(article.naddr).toMatch(