Windows packaging

WIP: based on !271 (merged) and !8 (merged)

Closes #307 (closed)

briar-desktop/src/packagingResources/linux/deb/copyright

+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+
+Files: *
+Copyright: 2021-2023 The Briar Project
+License: AGPL-3+
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+