Add a debian/copyright file

While the Debian package is far from compliant, let's try to sort out
the easy bits.

diff --git a/debian/copyright b/debian/copyright
new file mode 100644 (file)
index 0000000..1a11d28
--- /dev/null
+++ b/debian/copyright
@@ -0,0 +1,10 @@
+Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: mqttdeck
+Upstream-Contact: Jonathan McDowell <noodles@earth.li>
+Source: https://the.earth.li/gitweb/?p=mqttdeck.git;a=summary
+
+Files: *
+Copyright: 2023-2025 Jonathan McDowell
+License: GPL-3+
+ On Debian systems, the complete text of the GPL version 3 license can be
+ found in `/usr/share/common-licenses/GPL-3'.