Introduce REUSE compliance

This commit introduces REUSE compliance by annotating all files
with SPDX information and placing the reused licences in the
LICENSES folder.

We additionally removed the docheader tool which is made obsolete
by this change.

The main LICENSE and copyright text of the project is now not under
my personal name anymore, and it belongs to "The Respect Project
Contributors" instead.

This change restores author names to several files, giving the
appropriate attribution for contributions.

Author: alganet

.docheader

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: (c) Respect Project Contributors
+# SPDX-License-Identifier: MIT
+
 version: 2
 updates:
 

.github/dependabot.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: (c) Respect Project Contributors
+# SPDX-License-Identifier: MIT
+
 name: Continuous Integration (code)
 
 on:
@@ -84,9 +87,6 @@ jobs:
       - name: Install dependencies
         run: composer install --prefer-dist
 
-      - name: Run DocHeader
-        run: vendor/bin/docheader check library/ tests/
-
       - name: Run PHP_CodeSniffer
         run: vendor/bin/phpcs
 

.github/workflows/continuous-integration-code.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: (c) Respect Project Contributors
+# SPDX-License-Identifier: MIT
+
 name: Continuous Integration (docs)
 
 on:

.github/workflows/continuous-integration-docs.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: (c) Respect Project Contributors
+# SPDX-License-Identifier: MIT
+
 name: Release
 
 on: push

.github/workflows/release.yml

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: (c) Respect Project Contributors
+# SPDX-License-Identifier: MIT
+
+name: REUSE
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - '*'
+
+jobs:
+  reuse-check:
+    name: Compliance Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: '3.x'
+
+      - name: Install REUSE tool
+        run: pip install reuse
+
+      - name: Run REUSE check
+        run: reuse lint

.github/workflows/reuse.yml

@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: (c) Respect Project Contributors
+# SPDX-License-Identifier: MIT
+
 name: Update Regional Information
 
 on:

.github/workflows/update-regionals.yaml

@@ -1,3 +1,8 @@
+<!--
+SPDX-FileCopyrightText: (c) Respect Project Contributors
+SPDX-License-Identifier: MIT
+-->
+
 # Changes in Respect\Validation 2.x
 
 ## 2.3

CHANGELOG.md

@@ -1,3 +1,8 @@
+<!--
+SPDX-FileCopyrightText: (c) Respect Project Contributors
+SPDX-License-Identifier: MIT
+-->
+
 # Contributing
 
 Contributions to Respect\Validation are always welcome. You make our lives
@@ -54,8 +59,9 @@ and will natively have support for chaining and everything else.
 <?php
 
 /*
- * Copyright (c) Alexandre Gomes Gaigalas <alganet@gmail.com>
  * SPDX-License-Identifier: MIT
+ * SPDX-FileCopyrightText: (c) Respect Project Contributors
+ * SPDX-FileContributor Your Name <your_email@example.com>
  */
 
 declare(strict_types=1);
@@ -96,8 +102,9 @@ first item of the arrays:
 <?php
 
 /*
- * Copyright (c) Alexandre Gomes Gaigalas <alganet@gmail.com>
  * SPDX-License-Identifier: MIT
+ * SPDX-FileCopyrightText: (c) Respect Project Contributors
+ * SPDX-FileContributor Your Name <your_email@example.com>
  */
 
 declare(strict_types=1);

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) Alexandre Gomes Gaigalas <alganet@gmail.com>
+Copyright (c) Respect Project Contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal