feat: add hide menu bar items on macOS (#50)

Co-authored-by: V <vendicated@riseup.net>

src/shared/utils/guards.ts

@@ -0,0 +1,13 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0
+ * Vencord Desktop, a desktop app aiming to give you a snappier Discord Experience
+ * Copyright (c) 2023 Vendicated and Vencord contributors
+ */
+
+export function isTruthy<T>(item: T): item is Exclude<T, 0 | "" | false | null | undefined> {
+    return Boolean(item);
+}
+
+export function isNonNullish<T>(item: T): item is Exclude<T, null | undefined> {
+    return item != null;
+}