refactor(frontend): scripts -> utility

packages/frontend/src/utility/contains.ts

@@ -0,0 +1,14 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export default (parent, child, checkSame = true) => {
+	if (checkSame && parent === child) return true;
+	let node = child.parentNode;
+	while (node) {
+		if (node === parent) return true;
+		node = node.parentNode;
+	}
+	return false;
+};