docs: add OpenSSF Best Practices registration badge

Author: hyperpolymath

README.adoc

@@ -1,6 +1,11 @@
-// SPDX-License-Identifier: AGPL-3.0-or-later
+// SPDX-License-Identifier: MPL-2.0
+// Copyright (c) Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>
 // SPDX-FileCopyrightText: 2024-2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
 = RattleScript
+image:https://img.shields.io/badge/OpenSSF-Best_Practices-green?logo=openssourcesecurity[OpenSSF Best Practices,link="https://www.bestpractices.dev/en/projects/new?repo_url=https://github.com/hyperpolymath/rattlescript"]
+
+image:https://img.shields.io/badge/License-MPL_2.0-blue.svg[License: MPL-2.0,link="https://opensource.org/licenses/MPL-2.0"]
+
 :toc: preamble
 :icons: font
 
@@ -96,4 +101,6 @@ Alpha. The face transformer is implemented in `affinescript/lib/python_face.ml`.
 
 == License
 
-AGPL-3.0-or-later. See `LICENSE`.
+This project is licensed under the Mozilla Public License, v. 2.0. See the `LICENSE` file for details.
+
+SPDX-License-Identifier: MPL-2.0