Setting up REUSE: add copyright statements to files in collections/

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

collections/requirements.yml

@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2024 MDAD Team and contributors
+#
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
 ---
 collections:
   - name: community.general