Use Signal's spellcheck dictionary files

ts/test-node/util/createBrowserWindow_test.ts

@@ -0,0 +1,14 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+import { BrowserWindow } from 'electron';
+
+import { createBrowserWindow } from '../../util/createBrowserWindow';
+
+describe('createBrowserWindow', () => {
+  it('returns a BrowserWindow', () => {
+    const result = createBrowserWindow({ show: false });
+    assert.instanceOf(result, BrowserWindow);
+  });
+});