assets: adds license notices to all files

assets/res/style.css

@@ -1,3 +1,23 @@
+/*
+ * Copyright (c) 2022 Sasha Koshka <sashakoshka@tebibyte.media>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ *
+ * This file is part of Mintee.
+ *
+ * Mintee is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Affero General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * Mintee is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Mintee. If not, see https://www.gnu.org/licenses/.
+ */
+
 * {
 	box-sizing: border-box;
 	scrollbar-color: var(--accent) transparent;