Move licenses to LICENSES/, use SPDX-License-Identifier, mention all licenses in galaxy.yml (#491)

* Add SPDX license identifiers, mention all licenses in galaxy.yml.

* Add default copyright headers.

* Add headers for documents.

* Fix/add more copyright statements.

* Add copyright / license info for vendored code.

* Add extra sanity test.

* Add changelog fragment.

* Comment PSF-2.0 license out in galaxy.yml for now.

* Remove colon after 'Copyright'.

* Avoid colon after 'Copyright' in lint script.

* Mention correct filename.

* Add BSD-3-Clause.

* Improve lint script.

* Update README.

* Symlinks...

.github/workflows/docs-pr.yml

@@ -1,3 +1,8 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 name: Collection Docs
 concurrency:
   group: docs-${{ github.head_ref }}

.github/workflows/ee.yml

@@ -1,4 +1,8 @@
 ---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
 name: execution environment
 on:
   # Run CI against all pushes (direct commits, also merged PRs), Pull Requests