Added the files headers to the existing files in the project.

.env

@@ -1,3 +1,17 @@
+## ===----------------------------------------------------------------------===
+## 
+## This source file is part of the DiscogsService open source project
+## 
+## Copyright (c) 2025 Röck+Cöde VoF. and the DiscogsService project authors
+## Licensed under Apache license v2.0
+## 
+## See LICENSE for license information
+## See CONTRIBUTORS for the list of DiscogsService project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+## 
+## ===----------------------------------------------------------------------===
+
 # --- DOCUMENTATION ---
 
 DOCC_ARCHIVE_OUTPUT=./${SPM_LIBRARY_TARGET}.doccarchive