treewide: Add nice GPL-3.0-or-later license header

This change also ensures that this repo is reuse-3.0 compliant.

1 files changed, 14 insertions, 2 deletions

diff --git a/tests/README.md b/tests/README.md
index f789c990..34dc9255 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -1,6 +1,18 @@
+<!--
+nixos-config - My current NixOS configuration
+
+Copyright (C) 2025 Benedikt Peetz <benedikt.peetz@b-peetz.de>
+SPDX-License-Identifier: GPL-3.0-or-later
+
+This file is part of my nixos-config.
+
+You should have received a copy of the License along with this program.
+If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.
+-->
+
 # How to write a test
 
-Test are simple derivations, put into the `by-name` directory.  As you
+Test are simple derivations, put into the `by-name` directory. As you
 often want to test configuration, the 'standard' nixos-vm-test function
 starts a vm with the specified configuration and lets you run a python
 test script.
@@ -78,7 +90,7 @@ Sleep for `ARGS` seconds.
 
 #### `Expect`
 
-Grep the currently visible screen for the regex `ARGS`.  This regex
+Grep the currently visible screen for the regex `ARGS`. This regex
 must match.
 
 #### `ExpectNot`