Add header for another .sh file

Author: federicobucchi

scripts/prettify.sh

@@ -1,4 +1,17 @@
 #!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the Swift.org open source project
+##
+## Copyright (c) 2025 Apple Inc. and the Swift.org project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of Swift.org project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
 
 prettier --write \
   "assets/{javascripts/new-javascripts,stylesheets/new-stylesheets}/**/*.{js,scss}" \