Add vitest inside TypeScript

TypeScript/test/vitest/gilded-rose.spec.ts

@@ -0,0 +1,9 @@
+import { Item, GildedRose } from '@/gilded-rose';
+
+describe('Gilded Rose', () => {
+  it('should foo', () => {
+    const gildedRose = new GildedRose([new Item('foo', 0, 0)]);
+    const items = gildedRose.updateQuality();
+    expect(items[0].name).toBe('fixme');
+  });
+});