Added the Makefile and its respective .env files to the project.

.env

@@ -0,0 +1,22 @@
+# ===----------------------------------------------------------------------===
+# 
+# This source file is part of the Hummingbird DocC Middleware open source project
+# 
+# Copyright (c) 2025 Röck+Cöde VoF. and the Hummingbird DocC Middleware project authors
+# Licensed under the EUPL 1.2 or later.
+# 
+# See LICENSE for license information
+# See CONTRIBUTORS for the list of Hummingbird DocC Middleware project authors
+# 
+# ===----------------------------------------------------------------------===
+
+# --- DOCUMENTATION ---
+
+DOCC_GITHUB_OUTPUT=./docs
+DOCC_GITHUB_BASE_PATH=hummingbird-docc-middleware
+DOCC_PREVIEW_URL=http://localhost:8080/documentation/doccmiddleware
+DOCC_XCODE_OUTPUT=./${SPM_LIBRARY_TARGET}.doccarchive
+
+# -- SWIFT PACKAGE MANAGER ---
+
+SPM_LIBRARY_TARGET=DocCMiddleware