Update docs/ansible.md: add a copyright header

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

docs/ansible.md

@@ -1,3 +1,12 @@
+<!--
+SPDX-FileCopyrightText: 2019 - 2025 Slavi Pantaleev
+SPDX-FileCopyrightText: 2020 Hanno J. Gödecke
+SPDX-FileCopyrightText: 2020 Aaron Raimist
+SPDX-FileCopyrightText: 2022 Kai Biebel
+SPDX-FileCopyrightText: 2024 Suguru Hirahara
+
+SPDX-License-Identifier: AGPL-3.0-or-later
+-->
 
 # Running this playbook